Assailants fired four rockets into a city in northwestern Pakistan on Wednesday, killing 10 people and wounding 35, police said.

The rockets hit two houses, a mosque and a shop in Bannu, a troubled city in North West Frontier Province at about 2 a.m., said Khwaja Mohammed, a city police official.

Mohammed said 10 people died and that another 35 were wounded, including five police officers.

A doctor at the main hospital in Bannu said the bodies of nine people killed in the attack were brought there, while a resident said the death toll was higher because relatives had kept some of the bodies.

Both asked not to be named because of sensitivities surrounding the attack.

Mohammed described the attack as "terrorist activity," but said it was too early to say more about who was behind it.

Bannu and other cities in the northwest have seen a string of shootings and bombings blamed on Taliban militants who have been expanding their influence from strongholds in the tribal belt along the Afghan border.

Militant violence has spiked this month after a bloody raid on a radical mosque in the capital, Islamabad, and the redeployment of the army to North Waziristan, the tribal region closest to Bannu.