Islamabad, Pakistan ? Pakistan will send the United States DNA samples from the body of a man believed to have carried out a deadly grenade attack on a Protestant church, a government official said Tuesday.

Police are hoping that DNA testing can provide leads to the Sunday attack at the Protestant International Church, located in a heavily guarded diplomatic quarter near the U.S. Embassy. Five people died and 45 were injured, many of them foreigners.

The attack has prompted the U.S. State Department to issue a fresh warning to Americans to defer travel to Pakistan.

“The March 17 attack on worshippers at a church service in Islamabad underscores the possibility that terrorists may seek civilian targets,” the warning said.

Two Americans, an Afghan and a Pakistani were among the dead, but investigators have continued to focus on the fifth body, whose identity remains unknown. Officials are suspicious because no one among the congregation has been reported missing.

The torso of the suspected attacker, including his hands, was blown up, said Abdur Rasheed Khan, a senior Interior Ministry official.

“Apparently the attacker wasn’t on a suicide mission,” Khan told The Associated Press. “He wanted to escape, but a grenade exploded sooner than he expected.”

No arrests have been made.

Police want to use DNA testing to see if the fifth man was linked to a coat and tie found in one of the church’s bathrooms. That link would be important because it would suggest how a grenade-laden attacker might have slipped past the heavy security at the compound.

President Gen. Pervez Musharraf convened a meeting Tuesday of his top security officials and four provincial governors to review the case and the overall security situation in Pakistan.

No group has claimed responsibility, but suspicion fell on Islamic extremists who were outraged by Musharraf’s decision to cooperate with the United States during its war on terrorism. Attacks linked to militants have surged throughout the country in the months since Musharraf cracked down on five Islamic extremist groups.

The kidnap-slaying of Wall Street Journal reporter Daniel Pearl in January from the port city of Karachi was also considered part of an extremist campaign to embarrass the government and undercut Western support. Four people have been arrested.

Police were also investigating whether the church’s attacker was linked to Osama bin Laden’s al-Qaida terrorist network, a Pakistani newspaper reported. The newspaper, The Nation, said al-Qaida connections were one of several possibilities being examined.

President Bush has condemned the assault and a high-ranking State Department official cut short a visit to India to travel to Pakistan.

Assistant Secretary of State Christina Rocca and U.S. Gen. Tommy Franks, the commander of all coalition forces in neighboring Afghanistan, met briefly with Musharraf on Tuesday, the U.S. Embassy said. Details of the meeting were not disclosed.