Pakistani Taliban gunmen disguised in burqas have killed at least 13 people in an attack on a university campus in Peshawar, a local police chief has told Al Jazeera.

The army and local police summoned to the scene killed all attackers about two hours into the shooting, the military's press wing said.

Tehreek-e-Taliban Pakistan, the Pakistani Taliban, has claimed responsibility for the attack.

Mohammad Khorasani, a spokesman for the militant organisation, said they had targeted a safe house of the military's Inter-Services Intelligence agency.

The attackers arrived at the Agricultural Training Institute on Friday morning, before shooting and wounding a guard and entering the campus, Peshawar police chief Tahir Khan said.

A wounded student, Ahteshan ul-Haq, told Reuters the university hostel usually houses nearly 400 students, but most had gone home for a long holiday weekend and only about 120 students remained.

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"We were sleeping when we heard gunshots. I got up and within seconds everybody was running and shouting 'the Taliban have attacked'," he said.

Shehzad Akbar, medical director of Hayatabad Medical Complex, said six people died of their wounds and 18 were being treated. Another three people died at Khyber Teaching Hospital and 17 wounded were there, director Nekdad Afridi said.

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In December 2014, Pakistani Taliban gunmen killed 134 children at Peshawar's Army Public School, one of the single deadliest attacks in the country's history.

The Pakistani Taliban are fighting to topple the government and install a strict interpretation of Islamic law. They are loosely allied with the Afghan Taliban insurgents who ruled most of Afghanistan until they were overthrown by U.S.-backed military action in 2001.