The massive explosion that devastated the Marriott Hotel in Pakistan's capital, Islamabad, Saturday – killing at least 53 people and wounding hundreds – is being seen as a warning from Islamist militants over the Pakistani government's cooperation with the United States.
The hotel, which is popular with both diplomats and other foreigners, was struck by at least one truck filled with more than a ton of explosives in one of the country's worst acts of terrorism. The Czech ambassador and two Americans and about a dozen foreigners were among the dead.
"This was definitely a clear signal that this is no longer a safe place for foreigners, especially Americans," says Ayesha Siddiqa, an independent security analyst based in the city. "And it's a message to the Pakistani government: 'Can you handle us?' "
Though there was no immediate claim of responsibility for the attack, the main suspect is the Pakistani Taliban, which is made up of myriad Islamist militant groups and is believed to be linked to Al Qaeda.
Last month Ayman al-Zawahri, Al Qaeda's deputy leader, accused Pakistan's political leaders of acting on behalf of the US and called on his followers to rise up against them. But Saturday's explosion is also expected to exacerbate tensions between the US and Pakistan over how aggressively Pakistan is perceived to be cracking down on militants. A rising wave of violence has killed nearly 1,300 people in Pakistan this year alone.
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.
Saturday's blasts have underscored the extent to which Pakistan's government is torn between cracking down on militancy and placating angry Pakistanis who do not want to be dictated to by the US.
The recent US raids will have increased militants' desire to bomb targets like the Marriott, says Mahmood Shah, a former secretary of the Federally Administered Tribal Areas, where Pakistan's insurgency is centered. "The only way to curb these attacks is to strengthen the Pakistani government, strengthen the Army," he says.
Though the Marriott in Islamabad has been bombed twice before, Saturday's attack was the worse of its kind the city has ever seen. The last major attack to hit Pakistan's capital occurred on June 2, when a car bomb exploded outside Denmark's embassy, killing at least nine people. Now, Pakistanis worry more is to come.
"The terrible thing is that the structure for dealing with such attacks is very poor," says Ms. Siddiqa, the security analyst, pointing out that in television footage of the Marriott in the hours after the blast, there was little sign of an efficient emergency fire service.
"I drove with my husband to the airport that evening, expecting to have to go through heavy security – and all the check posts had been abandoned," she adds, "The police are demoralized and there's a general weakening of law and order."
Others speculated, however, that the attack on the Marriott may do little to engender sympathy with Al Qaeda or Taliban aims.
Many of those killed and injured Saturday are likely to have been Pakistanis who had gathered at the hotel for the communal iftar meal – the breaking of the holy Ramadan fast.