Washington ? The State Department Friday ordered all but essential employees at the U.S. Embassy and three consulates in Pakistan to return home, a move that signaled serious concern with security in the country.

The order was issued five days after an embassy employee and her 17-year-old daughter were among five killed in a grenade attack on a Christian church in the diplomatic quarter of Islamabad, the Pakistani capital.

Secretary of State Colin L. Powell, traveling with President Bush in Monterrey, Mexico, telephoned Pakistani President Pervez Musharraf Friday to inform him of the decision, State Department spokesman Philip T. Reeker said.

Powell told Musharraf that the order didn’t reflect a lack of confidence in his government, its security force or Pakistan’s commitment to protecting Americans, Reeker said.

Nevertheless, the move underscores mounting worries that Americans face a likelihood of future attacks in a country that has emerged as a critical U.S. ally in the region but remains a political tinderbox.

Since Sunday’s attack, Reeker said, the department has been reviewing security surrounding its diplomatic facilities in Pakistan as well as “a continuous flow of threat information through intelligence channels.”

Recent State Department advisories had already warned U.S. travelers to avoid Pakistan.

The department’s facilities in Pakistan include the embassy in Islamabad, as well as consulates in the cities of Lahore, Karachi and Peshawar. All four posts will remain open, Reeker said. But children and other dependents of State Department employees, as well as workers whose jobs aren’t critical, will be required to leave.

Reeker declined to say how many will be affected by the evacuation.