A BURQA-CLAD female suicide bomber attacked police at the scene of an earlier explosion in northwestern Pakistan on Thursday, twin strikes that killed five people and broke a relative lull in militant violence in the country.

Islamist extremists with links to al-Qaeda have waged a bloody campaign against Pakistan’s pro-Western rulers since 2007, targeting police, government and Western targets. Up to 35,000 people have been killed, raising fears abroad over the stability of the nuclear-armed nation.

In the first incident today, a remote-controlled bomb exploded in Peshawar’s Lahori Gate area as a police truck carrying constables about to start their shift drove by. Four police officers and a boy passing by were killed, while 22 people were wounded.

An hour later, two women approached police guarding the area. One of the females threw a grenade, then was able to partially detonate her suicide vest, said Shafqat Malik, a police officer with the bomb disposal unit. She appeared to be 16 or 17 years old, he said.

“I thought the girl was pregnant as she was walking slowly with another woman. As I tried to push people away, suddenly a blast took place,” said police officer Himayat Ullah, who was wounded in the attack.

Attack tactics

Compared to other periods over the last four years, Pakistan has seen few large militant attacks over the last two months. Even with this lull, however, no one has suggested that the country’s stretched and poorly trained security forces were making progress in the fight.

Most of the militants are based in the northwest close to Afghanistan, and Peshawar — the largest town in the region — has been frequently hit.

The tactics deployed in the attack — deploying a female bomber to return to the scene of an earlier blast to target officers there — showed a degree of sophistication, but were not unprecedented.

In June, militants said they had sent a husband and wife suicide squad to a police station in another northwestern town. That attack killed 10 people. Late last year, a female suicide bomber attacked a World Food Programme food distribution center in the region, killing 45.