KABUL, Afghanistan » Militants attacked the American University of Afghanistan today, according to an Associated Press photographer who was in class at the time.

Massoud Hossaini said he was in a classroom with 15 students when he heard an explosion on the southern flank of the campus.

“I went to the window to see what was going on, and I saw a person in normal clothes outside. He shot at me and shattered the glass,” Hossaini said, adding that he fell on the glass and cut his hands.

The students then barricaded themselves into the classroom, pushing chairs and desks against the door, and staying on the floor.

Hossaini and about nine students later managed to escape from the campus through a northern emergency gate.

“As we were running I saw someone lying on the ground face down, they looked like they had been shot in the back,” he said.

Hossaini and the nine students took refuge in a residential house near the campus, and were later safely evacuated by Afghan security forces.

University President Mark English told The Associated Press that security forces had arrived on the scene soon after the attack began around 7 p.m. (1430 GMT) and that “we are trying to assess the situation.”

Other witnesses say they heard explosions and automatic gunfire. Ambulances arrived at the campus in western Kabul, but it was not immediately clear how many people had been wounded.

Dejan Panic, the program director at Kabul’s Emergency Hospital, said 11 patients had so far been admitted, 10 men and one woman. He said three were “seriously” wounded, probably from automatic gunfire.

Police spokesman Sediq Sediqqi said security forces were conducting a clearing operation to track down the “terrorists.” He said it was still not clear if there were one or two attackers.

All other personnel on the campus were being evacuated, he said. He had no further details on the nature of the attack.

The Pentagon said U.S. military advisers were on the ground with Afghan security forces at the university. Spokesman Adam Stump said the forces had been embedded with the Afghan units.

The attack on AUAF comes two weeks after two university staff, an American and an Australian, were kidnapped from their car by unknown gunmen. Their whereabouts are still unknown.

The university was established in 2006 to offer liberal arts courses modeled on the U.S. system. More than 1,000 students are currently enrolled in degree courses.

The Taliban have been fighting to overthrow the Kabul government for 15 years, and regard foreign civilians as legitimate targets.

Associated Press writers Rahim Faiez in Kabul, Afghanistan, and Lolita C. Baldor in Washington contributed to this report.