Pakistani police say bomb has exploded in a Sunni mosque in the northwest, killing at least four people and wounding more than 25 others. Senior police officer Imtiaz Khan says the bomb was planted in a bookshelf inside the mosque in Peshawar. Khan says the remote-controlled bomb was detonated when noon prayers started in the mosque.

Peshawar, the capital of Khyber Pakhtoonkhwa province, has been the site of several terrorist attacks in recent months.

The city is surrounded by lawless tribal regions where al-Qaeda and Pakistani Taliban have hideouts.

The Pakistani military has carried out several operations in the area, but intermittent terrorist attacks continue.