Gunmen attack prison in Pakistan From Zahir Shah Sherazi, For CNN July 30, 2013 -- Updated 0024 GMT (0824 HKT) NEW: The Pakistani Taliban claims responsibility for the attack Sixteen explosions were heard, power supply was cut, officials say Four people were injured, including three civilians Some 5,000 prisoners are held at the prison in northwestern Pakistan (CNN) -- Gunmen wearing police uniforms attacked a central jail in northwestern Pakistan early Tuesday, according to Shoukat Yousafzai, the Khyber Pakhtunkhwa information minister. Four people were injured, including three civilians, at the prison in the city of Dera Ismail Khan. Sixteen explosions were heard. Some 5,000 prisoners are held at the prison, 40 of whom are considered high-profile militants. The gunmen cut off the prison's power supply, then launched the attack from all sides, Malik Qasim Khan, an adviser to the chief minister on prisons, told CNN. The Pakistani Taliban claimed responsibility for the attack. Spokesman Shahidaullah Shahid said that the group freed around 300 prisoners, a claim Pakistani army officials denied. Shahid described the operation as a success.