Pakistan blast kills at least 10 : A police checkpoint in the northwestern city of Peshawar is hit by a suicide bomber; more than 20 are injured.

A suicide attacker set off a car bomb at a police checkpoint Saturday, killing at least 10 people, officials said.

The city of Peshawar, near the Afghan border, has seen several bomb attacks since the army began an offensive against the Taliban in South Waziristan last month. Militants have hit back by stepping up attacks on towns and cities, killing several hundred people.

“The car bomber approached a barrier near the police check post, and then it exploded,” said city official Sahibzada Anis. Among the 10 dead were two police officers, he said, and more than 20 people were wounded.

Pieces of the bomber’s car littered the road. Several other vehicles were heavily damaged, with one flipped onto its roof. There was no immediate claim of responsibility for the blast.

The army offensive in South Waziristan is aimed at rooting out Pakistani Taliban militants. The United States says Pakistani government action against militants in border enclaves is vital for the U.S. effort in neighboring Afghanistan.

On Friday, a suicide car bomb exploded at an office of Pakistan’s main intelligence agency in Peshawar, killing at least 10 people. The Taliban said it carried out that attack, as well as a suicide bombing at a police station in the northwestern town of Bakkakhel in which seven people were killed.

“We will carry out similar attacks in other parts of the country,” Qari Hussain Mahsud, a senior Pakistani Taliban member and a cousin of Taliban chief Hakimullah Mahsud, said in a telephone interview.

The military says it has killed more than 520 militants in the offensive in South Waziristan, including seven Saturday.

Soldiers have advanced into the militant heartland from three directions and captured several Taliban base areas in the region of barren mountains, ravines and patchy forest.

There has been no independent verification of casualties. Reporters and other independent observers are not allowed in the conflict zone except on occasional trips with the military.