DERA GHAZI KHAN: A suicide car bomb exploded in a market close to the home of a politician in Pakistan's most populous province Tuesday, killing 22 people and wounding 70 others.

The blast in the Punjabi town of Dera Ghazi Khan was the latest in a series of attacks by Taliban militants avenging an army offensive against insurgents in the northwest. More than 500 people have been killed.

The attacker detonated his explosives outside the house of the lawmaker, who was not at home at the time. Most of the dead and injured were people shopping or working at the market. It was unclear whether the bomber targeted the politician's home or the market.

The attack badly damaged the house and several nearby shops and buildings, including a mosque and bank.

As night fell, people searched through the debris for survivors trapped under the rubble.

"The whole market has collapsed," said Raza Khan, a local resident. "There is smoke and people running here and there."

Rescue official Natiq Hayat said 22 people were killed and 70 wounded. Government official Hasan Iqbal said the attack was carried out by a suicide bomber.

The lawmaker whose home was hit, Zulfiqar Khosa, is a senior member of the Pakistan Muslim League-N party, which is in charge of the Punjab government but is in the opposition in the federal government.

Police and politicians in Punjab are under pressure to crack down on militant networks that have long recruited in its poor villages and Islamic boarding schools.

The militants have staged several attacks in Punjab to illustrate their reach across the country, far beyond the northwest tribal regions bordering Afghanistan. Dera Ghazi Khan district is in Punjab but borders the country's other three provinces.

Zulfiqar Khosa's son, Dost Mohammad Khosa, said two of his cousins were among the wounded.

"It was a direct attack on us," Dost Mohammad Khosa alleged, declining to speculate who was behind the blast.

Iqbal said he doubted the house was the target, speculating the attacker simply wanted to spread terror in the town.

Militants have mostly targeted security forces in recent months, but lawmakers and court buildings also have been attacked. There have also been at least three bombs in crowded markets, apparently aimed at causingcivilian casualties and undercutting public support for the army offensive.