ISLAMABAD - Suicide bombers and attackers with rocket-propelled grenades assaulted a prison in Pakistan, allowing 250 inmates - including top militants - to escape, police and Taliban sources said early Tuesday.
At least eight policemen were killed, and 21 people - including civilians - were injured in the attack, which began shortly before midnight local time (3 p.m. ET) Monday.
Fighting and explosions could still be heard into the early hours of Tuesday, and security forces had imposed a curfew in order to protect civilians in the city of Dera Ismail Khan, Shaukat Yousafzai, a spokesperson for Khyber Pakhtunkwa province told NBC News.
The number of militants, if any, that escaped was unclear and could not be independently verified.
The Pakistani Taliban claimed it had released 250 prisoners during the attack on the jail complex in the mid-sized frontier town, 200 miles west of Lahore, which borders the volatile South Waziristan tribal area.
Mushtaq Jadoon, the local civil commissioner, told Reuters the escaped prisoners included 30 top militants and six people on death row. Those who escaped are believed to have been whisked away to the lawless tribal areas of South and North Waziristan.
Yousafzai said militants dressed in police uniform attacked the heavily-guarded prison but were repelled. More than 3,000 inmates are held at the prison.
"We received eight bullet-riddled bodies of policemen and 21 injured so far," said Dr Rab Nawaz, a doctor at Dera Ismail Khan's main hospital, adding that some of the injured were in a critical condition.
Pakistan Taliban spokesman Shahidullah Shahid said that, soon after entering the prison, the attackers destroyed a power supply system of the jail and started calling names of known prisoners through loud speakers to escape.
"Major part of our operation is over and we succeeded in freeing our 250 prisoners from the jail. This was our aim but our suicide bombers are still present inside the jail and offering tough resistance to the military forces and police to enter the prison," he said.
He claimed they had planned the attacks a few months ago to release their "important" senior leaders from the jail.
Provincial prisons chief Khalid Abbas told Reuters that there were up to 40 gunmen wearing police uniforms who launched the attack, destroyed a power line and detonated heavy explosions that breached the outer walls.
"It's completely dark in there. We don't know what's going on but there is fighting," he said.
The militants fought their way inside using rocket-propelled grenades and machine guns, district police chief Sohail Khalid told Reuters.
A senior security official in Peshawar said militants were planning a "Bannu" like attack on the jail to release prisoners. A high profile jail break occurred in 2012 in nearby Bannu, where several Taliban and other militants, including those involved in assassination attempts on former president Pervez Musharraf, were freed.
Jeff Black of NBC News and Reuters contributed to this report.