Police said prisoners clashed with each other but did not give the reason for the incident. They said the clashes continued for some time, after which the army was called in.
The Central Jail in Peshawar is home to over 48 members of the banned Tehrik-e-Taliban Pakistan.
Shakil Afridi, the doctor who helped the US track down Osama bin Laden before he was killed in Abbottabad in 2011, is also being held at the prison along with Tehrik-e-Nifaz-e-Shariah-e-Muhammadi chief Sufi Muhammad and 200 members of Lashkar-e-Islam.