India, too, believes it is feeling the effect of Pakistan's mounting insurgency. On the day of the Islamabad bombing, police in New Delhi claimed that the Pakistani Islamist militant group, Lashkar-i-Tayyaba, was behind bombs that ripped through busy Delhi markets on Sept. 13, killing at least 22 people.
On Sunday, authorities in India announced the arrest of three suspects in the bombing claimed by the Indian Mujahideen, a group that has claimed to carry out other large attacks in recent months. But Indian authorities say they are acting under the direction of Lashkar-i-Tayyaba.
In a bid to root out militants from Pakistan's tribal areas that border Afghanistan, the US has recently begun to carry out cross-border raids from Afghanistan, a move that has infuriated many Pakistanis.
Hours before Saturday's attack on the Marriott, Pakistan's newly elected president, Asif Ali Zardari, made his first speech to parliament since he succeeded Pervez Musharraf, in which he described terrorism as "a cancer" that Pakistan was determined to fight.
In a clear allusion to the US raids, Mr. Zardari, who is scheduled to meet President Bush next week, also pledged to resist violations of the country's sovereignty.
"We will not tolerate the violation of our sovereignty and territorial integrity by any power in the name of combating terrorism," he said, as legislators thumped their desks and cheered in support.