The Salvadorean Air Force is using incendiary bombs against the civilian population in the zone around the Guazapa Volcano, according to people who recently fled the area, troops who operate in the zone, and a European doctor who examined two civilians who say they were wounded during an attack.
The descriptions of the effects of the bombs fit the known effects of napalm (jellied gasoline) and white phosphorus bombs.
Salvadorean officials, however, deny the existence of incendiary bombs in the Air Force's arsenal. And United States officials say no such bombs have been supplied to the Salvadoreans.
''We do not have incendiary bombs,'' says Col. Ricardo Aristides Cienfuegos, the spokesman for the Joint Chiefs of Staff. ''I have never seen these types of bombs since my arrival in this post in June 1983. Before that, I don't know.''
''We do not supply incendiary bombs to the Salvadoreans,'' United States Embassy spokesman Greg Lagana says. ''The only incendiary device is the white phosphorus rocket used to mark an area for bombing. This rocket can cause a fire in a dry area.''
The chief of operations for the Air Force, Captain Barrera, refuses to comment on the charges, saying that all statements from the armed forces must be made by the press office for the Joint Chiefs of Staff. ''If you've talked to the US Embassy,'' Barrera says, ''why do you need a statement from us? Who do you believe more, the subversives or the embassy?''
Those who contend they have survived incendiary bomb attacks in recent weeks say the bombs are dropped by helicopters, light aircraft, and A-37 Dragonfly jet fighter-bombers. These incendiary bombs apparently vary in size from rockets to much larger containers. Incendiary devices may also be included in the casings of normal fragmentation bombs, survivors contend.
Civilians from the zone refer to the incendiary material in the bombs as ''flaming liquid.'' They distinguish between two types of the ''flaming liquid.'' One type appears to resemble napalm, the other, white phosphorus.
''The worst bomb is the one that shoots out fire and cannot be put out,'' says a man who recently fled from the town of Guadalupe, which some former residents say was destroyed by incendiary bombs two weeks ago. ''This bomb has a strong, bitter smell, and when pieces of the flaming liquid land on you, they eat deep into your flesh and travel along your body.''
Residents contend that if water is put on a wound caused by this type of bomb , the burning will continue. They say they must shield their nose and mouth with a damp cloth to lessen the effect of toxic fumes.
''When burning white phosphorus enters the body, it keeps on burning,'' Dr. Matthew Meselson, a Harvard University biochemistry professor who is an expert on chemical weapons, said in a telephone interview. ''It will burn under water, and actually burn inside the body. It can be a horrible antipersonnel weapon. The white phosphorus will also emit acidy fumes, and the effect of the fumes could be reduced by the use of a wet handkerchief over the mouth.''
Residents from the zone say the second type of incendiary bomb creates clouds of black smoke that take away available oxygen. They say it shoots out larger jets of flaming liquid. They contend this bomb leaves an oily film over the water and along the ground.
''From the description,'' says Dr. Meselson, ''it sounds like napalm. Napalm burns at a much higher temperature than white phosphorus. The oily film could be from napalm residues on the ground.''
''The United States and other countries,'' he says, ''have stockpiled large quantities of napalm, white phosphorus, and related flame weapons since the Vietnam war.''
Dr. Meselson also says such weapons could easily be devised on the battlefield. And he and others note that napalm could be used in conjunction with ''Iron'' bombs.
Salvadorean military officials acknowledge that their armed forces have the capability to make napalm bombs.
The Salvadorean Air Force, according to military officials here, is equipped with 250-, 500-, and 750-pound explosive ''Iron'' bombs. The Air Force recently acquired antipersonnel ''Iron'' bombs that explode about a yard above the ground , according to these sources. All of these bombs are fragmentation bombs.
''Usually we drop incendiary bombs before we begin operations in the area around the volcano,'' a soldier from the 5th Infantry Brigade says, standing with several of his companions at the rear guard of a firefight near Tenancingo, southeast of the volcano. ''By the time we enter the area, the land has been burned over and the subversives pretty well toasted.''
Soldiers in the Atlacatl Immediate Reaction Battalion also contend that incendiary weapons are used before large-scale operations in the zone. Soldiers from both the Atlacatl and 5th Brigade say they have seen small villages in the area burned to the ground and large tracts of land charred by incendiary bombs.
''We have holes dug in the ground outside our villages to hide in when the planes come,'' says a person displaced from the town of Guadalupe, ''and we keep the children near the holes or in them all day. At first the Air Force dropped bombs that knocked down trees and houses, killed people, and made a three-meter crater. Then they began to drop bombs that exploded before hitting the ground and others that made craters eight meters deep to kill us as we hid in our shelters. Now they use the worst bomb of all - the flaming liquid.''
''I was outside my house when the bomb fell,'' a woman says. ''I could not see anything because of the black smoke and could not get air. Everything was on fire. My two children burned to death.''
This woman contends she was wounded by this bomb. She has several large areas of scar tissue on her body.
Dr. John Constable, a burn expert at Massachusetts General Hospital who has treated victims of incendiary bombs in Vietnam, said in a telephone interview, ''Napalm will burn in large patches along the surface of the skin where it makes contact. The burns are different than those of white phosphorus, which are more profound wounds that often resemble the pattern left by a shotgun wound.''
Another person who says she is a victim of an incendiary bomb attack has scar tissue that resembles several large discolored welts patterned like a ''shotgun wound.'' She says her family was killed by the bomb that inflicted her wounds.
''I have treated many victims of bomb attacks,'' says a European doctor who specializes in war injuries and who examined the two women, ''and the wounds of these two victims do not correspond to wounds incurred from normal fragmentation bombs. These people were burned by an incendiary substance. It is now impossible for me to determine exactly what that substance was, but it was probably napalm, and in the case of the more profound wounds, white phosphorus.''
Civilians from the zone hit by these bombs speculate that the Air Force is dropping incendiary weapons to force them out of a guerrilla-controlled area. Many small villages and fields in the area are now burned, they say.
''These bombs,'' says one man, ''not only burn down our villages and homes, but our plots of land. We are left, after the attack, with nothing.''
This is not the first time the Salvadorean Air Force has been charged with using incendiary bombs. Residents of the Guazapa area appealed to human rights groups after a large military operation in February 1983, known as ''Guazapa Ten ,'' resulted in incendiary bomb attacks. There are charges they have been used on other occasions, too.
The then-president of the Salvadorean Commission on Human Rights, -Marianel- la Garcia Villas, went into the zone to investigate the charges. People who accompanied her on that trip say she and several other civilians were killed by soldiers from the Atlacatl Battalion as she was leaving the zone on March 14, 1983. At the time she was killed, Garcia reportedly was carrying tape-recorded testimonies from victims of incendiary bomb attacks, photographs she had taken, and soil samples that she thought contained residues left by incendiary bombs.
One of those with Garcia says she recovered the tapes, photos, and samples from the body and fled.
After the ''Guazapa Ten'' operation, the number of incendiary bomb attacks dropped for a while, say those who live in the zone. But they contend such bomb attacks have increased in recent weeks.
This story is also being published by Pacific News Service.