By Mustafa Andalib
GHAZNI, Afghanistan (Reuters) - Taliban insurgents stormed a prison in Afghanistan on Monday, killing police and releasing more than 350 inmates, including nearly 150 deemed a threat to national security, and then attacked troops rushing to help, officials said.
The latest Taliban prison raid, on the outskirts of the central city of Ghazni, comes after setbacks for the government in different parts of the country and deadly attacks in Kabul which have dashed hopes for peace talks.
A Reuters reporter outside the mud fort prison in Ghazni, 120 km (75 miles) southwest of the capital, Kabul, saw the bodies of two men who appeared to be suicide bombers and a blown-up car that had apparently been used to destroy the main entrance.
Clusters of bullet casings were scattered across the road.
The interior ministry said that 355 of the 436 prisoners had escaped.
Of those who got away, 148 were a "threat to national security and 207 were criminals", the ministry said in a statement.
Four Taliban and four members of the security forces were killed in the attack, the ministry said. Seven police were injured.
Mohammed Ali Ahmadi, deputy city governor, said the prison's security was well below recommended standards because it was so close to Ghazni - only seven km (4.3 miles) from the city center - and it was believed that reinforcements would get there quickly in the event of trouble.
On Sunday, officials concerned about a breakout had transferred 18 "dangerous" Taliban to a jail operated by the Afghan intelligence agency, he said. Seventeen were left behind.
Ahmadi said he believed they helped coordinate the attack.
"Roads to the prison were covered with land mines in advance to avoid reinforcement," Ahmadi told reporters. "An army vehicle coming for reinforcements was blown up by a roadside bomb while trying to reach the prison."
One security official said the attackers, armed with rocket-propelled grenades and automatic rifles, were wearing security force uniforms.
Taliban spokesman Zabihullah Mujahid said gunmen and three suicide bombers attacked the prison at 2 a.m. (2200 GMT Sunday). Three bombers were killed, he said.
"Important military mujahideen officials have been freed," he said.
The Taliban are fighting to overthrow the foreign-backed government of President Ashraf Ghani, expel foreign forces and impose their strict interpretation of Islamic law.
The insurgents have attacked jails to free hundreds of prisoners including their comrades on several occasions, in both Afghanistan and neighboring Pakistan.
Security at Afghan prisons is often poor, with untrained, poorly equipped police guarding crumbling facilities.
(Writing by Mirwais Harooni; Editing by Katharine Houreld, Robert Birsel)