Kabul, (IANS) : Twelve people were killed in an attack on the American University of Afghanistan in Kabul, a spokesman for the Chief of Kabul Police told CNN on Thursday.

Seven students, three policemen and two security guards were killed in the attack on the American University campus, Basir Mujahid, the spokesman said.

Thirty-five students and nine police were injured and about 750 students and staff were rescued, Kabul police chief Abdul Rahman Rahimi told the BBC.

Police searched the American University of Afghanistan early Thursday about 10 hours after the assault began and killed two of the attackers who stormed the campus with guns and explosives.

The gunmen detonated explosives and fired guns, witnesses said, causing some students and faculty to flee. Others hid inside buildings, a senior State Department official told CNN.

No group has claimed responsibility.

Police described the attack, which began at about 7 p.m., as “complex”. Special forces were on the scene along with American military advisers, the BBC said.

One of those trapped inside the university for several hours was Massoud Hossaini, a Pulitzer Prize-winning photojournalist, who tweeted his experience and pleaded for help.

Student Ahmad Mukhtar told the BBC that he was 100m away from the university’s main entrance on his way home when he heard “six or 10” shots and a “huge” blast.

The explosion created so much light that it momentarily lit up the surrounding area, he said.

“I climbed a six-metre wall to escape,” Ahmad said.

Other trapped students and staff tweeted or posted on Facebook their desperate pleas for help.

The attack comes two weeks after two university staff – one American, one Australian – were kidnapped by unknown gunmen. Their whereabouts remain unknown.

The school opened in 2006. It’s the only private, nonprofit coed university in the country and has about 1,700 full- and part-time students, CNN reported.