Aftermath of the Shangla suicide attack. AP photo.

The Taliban followed up last weekend's assault on the Army General Headquarters with a massive suicide attack at a market in the northwestern district of Shangla.

The suicide bomber detonated his car packed with explosives as a military convoy passed through a checkpoint in a market in Alpuri in Shangla. Forty-one people, including six security personnel, were killed in the attack, said Mian Iftikhar Hussain, the information minister for the troubled Northwest Frontier Province, according to Dawn. "Twelve of the injured are in serious condition," Hussain added.

The Shangla suicide attack is the fourth major strike in Pakistan this week. On Oct. 5, a suicide bomber killed five UN workers in an attack at the World Food Program office in Islamabad. On Oct. 9, a suicide bomber killed 49 civilians in an attack at a bazaar in Peshawar. On Oct. 10, an assault team attacked the Army General Headquarters and took 42 security personnel captive. Eleven soldiers were killed, including a brigadier general and a lieutenant colonel, along with nine members of the assault team; and 39 hostages were freed.

Today's attack in Shangla is the latest in a region the military recently proclaimed to be cleared of the Taliban. Earlier this year, the military launched an offensive against Taliban forces led by Mullah Fazlullah, the radical leader of the Taliban in Swat and the surrounding districts of Dir, Buner, and Shangla. Six of the 21 top Taliban leaders wanted by the government have been killed or captured, but Fazlullah and some key military commanders are still on the loose.

The Swat Taliban dispersed its forces in the region as the military launched its offensive. Since April, the Taliban have established bases in the districts of Shangla, Mansehra, Haripur, Battagram, Mardan, and Swabi. Taliban units ranging from 50 to 150 fighters fanned out through the districts with no resistance from the military, despite the military's claim it had established blocking positions to prevent the Taliban from retreating from the battlefield and bleeding into bordering districts.

The military says an offensive against the Taliban in South Waziristan is imminent. Yesterday 16 Taliban fighters were killed in an airstrike in South Waziristan. But the military will move only against the Mehsud branch of the Taliban, and will leave Taliban commanders Mullah Nazir and Hafiz Gul Bahadar and the Haqqani family untouched.