PESHAWAR, Pakistan?Islamist militants blew up a girls school in Pakistan's lawless Khyber tribal district Sunday, destroying the building and wounding four people in neighboring homes, officials said.

Two explosions ripped through the 18-room government high school for girls at Kari Gar village and a boy who watched the premises is missing, possibly kidnapped by the militants, local administration officials said.

"The militants have blown up the school with two blasts and all rooms were demolished," said administration official Shafeer Ullah.

"Four people in neighboring houses were also wounded and their homes slightly damaged. We're still trying to find out what happened to the office boy," Ullah told AFP.

Another of Khyber's administrators, Farooq Khan, confirmed the incident.

Islamist militants, who have carved out a strong presence in Pakistan's semi-autonomous tribal belt on the Afghan border, have destroyed hundreds of schools, mostly for girls, in the northwest of the country in recent years.

Nearly 200 schools were destroyed in the Swat valley alone during a two-year Taliban uprising to enforce sharia law in a district once favored by Western tourists for its ski slopes and bracing mountain air.

Following up a similar offensive in Swat this summer, Pakistan has been fighting against homegrown militants in Khyber and pressing a major assault designed to crush Taliban sanctuaries in South Waziristan.

Authorities last month shut schools across Pakistan following a suicide attack on a university campus in Islamabad, although most have since reopened.