Investigators have confirmed security lapses by Pakistani police in a grenade attack against a Protestant church last month that killed five people, including two Americans, government officials said on Saturday. A lone assailant armed with grenades managed to pass through a police checkpoint at the entrance to the capital's iplomatic quarter and past two officers stationed outside the Protestant international church, senior interior ministry officials said on condition of anonymity. The attacker then hurled several grenades into the packed church and disappeared, they said. One body has not been identified and may have been the assailant. The officials declined to elaborate further ahead of an interior ministry report outlining how law enforcement agencies failed to prevent the March 17 attack. The report is due to be submitted to President Pervez Musharraf on Monday. But officials said that security has already been stepped up at the guarded enclave, where many foreign diplomats live and work. Soldiers have been deployed outside foreign missions, and police-issued passes are now required to enter the area. Interior ministry and army investigators missed an April deadline to submit the report, pleading a heavy workload. In addition to investigating the church attack, Pakistani and US agents have been involved in a series of raids against suspected al-Qaida hideouts, arresting more than 100 people, including a top lieutenant of Osama bin Laden. Bureau Report