Fighting on Wednesday erupted after a landmine blast hit an army vehicle and injured three soldiers, Pakistani officials said.

A military official said 11 people were arrested after the clash in the main market of the town of Wana in the South Waziristan tribal region.

Wana is about 400 km southwest of the capital, Islamabad.

"After the blast, the miscreants opened fire on troops who then returned fire and cordoned off the area," said an official, who asked not to be named.

The identity of the dead was not immediately known.

Embattled zone

South Waziristan has been the scene of major operations by the Pakistani army in recent months.

Pakistan says there are hundreds of suspected al-Qaida-linked foreign fighters, officials say.

More than 200 people were killed in operations in the region in March and June.

Officials say many fighters have fled South Waziristan and have taken shelter in major Pakistani cities.

The security forces have launched a massive crackdown against suspected al-Qaida-linked fighters in urban areas and have arrested more than 70 suspects since July.