Militants have launched an attack on the American University in Afghanistan's capital, Kabul, with students and teachers trapped inside the classrooms.
According to early reports at least one person has been killed in the attack and 14 others have been wounded.
An official with the Afghan Interior Ministry confirmed that a series of powerful explosions and gunfire were heard at the university campus on Wednesday evening
Afghan police commanders have described the raid as "a complex attack."
"We have been notified of a complex attack on the American University on Darul-Aman Road," the commander of Kabul police's quick reaction force told NBC News, adding, "We still don't know the exact nature of the attack."
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."
“I heard explosions and gunfire is going on close by," a desperate student told AFP by telephone, adding, "We are stuck inside and very afraid."
Many other trapped students were tweeting desperate messages for help.
Police spokesman Sediq Sediqqi police and intelligence agency personnel are at the campus and "are trying to search for the terrorists."
He said police are also trying to evacuate all personnel from the campus. He had no further details on the nature of the attack.
No group or individual has claimed responsibility for the attack so far.
The attack comes after two professors at the university -- an American and Australian -- were kidnapped in the heart of Kabul earlier this month. Their whereabouts are still unknown.