Islamabad, June 27 (DPA) At least six militants were killed in a US drone attack in Pakistan’s restive northwestern tribal region Sunday, a security official said.

The pilotless aircraft struck in Tabbi Tool Khel area near Miran Shah, the major town in North Waziristan, a known hotbed of Taliban and Al Qaeda militants.

The intelligence official said two missiles were fired at an Islamic seminary, Shoaib ul Aloom, frequently by Taliban fighters conducting cross-border raids on NATO-led international forces in Afghanistan.

‘The reports that we have received from our informants, six militants were killed and three wounded,’ said the intelligence official, who spoke on condition of anonymity.

‘The death toll may rise as locals believe more bodies are buried under the rubble,’ added the official. ‘Efforts are under way to pull them out.’

The seminary was headed by a local Taliban leader Amir Hamza, who apparently survived the strike.

The US has increased drone strikes in North Waziristan, regarding the district as a base for militants conducting cross-border attacks on NATO troops in Afghanistan.

Officials say more than 900 militants have been killed in over 100 CIA-operated airstrikes in tribal areas near the Afghan border since mid-2008. Some victims were civilians.

Washington considers drones an important tool in its fight against terrorism despite strong protest from Pakistan, a key US ally.