At least two people were killed and 13 wounded Sunday in an explosion at a building where a Pakistani

They said the Punjab home minister Shuja Khanzada was still trapped with several others under the rubble after the blast brought down the roof of the building in the village of Shadi Khan in Attock district, 70 kilometres (43 miles) northwest of Islamabad.

The minister was meeting the people at the time, Nabila Ghazanfar, a police spokeswoman, told AFP.

She said rescue services had reached the scene but there was no news yet about the minister's condition.

It was not immediately clear what caused the explosion, the spokeswoman said.

Live television footage showed a crane being used to remove the rubble.