Nairobi: Gunmen attacked a college campus in northeast Kenya on Thursday, opening fire in dormitories and killing at least 15 people and wounding 29 others, witnesses said. The attack bore the hallmarks of a Somali Islamic extremist group.

Augustine Alanga, a 21-year-old student who survived the attack at Garissa University College, described a panicked scene as gunshots rang out outside their dormitory in the pre-dawn hours when most people were still fast asleep.

The shooting became more intense almost immediately, he told The Associated Press by phone. The heavy gunfire forced some students to stay indoors as others fled with gunmen firing at them. He said he saw at least five heavily armed, masked gunmen.

"I am just now recovering from the pain as I injured myself while trying to escape. I was running barefoot," said Alanga, who was one of scores of students who managed to escape through barb-wire fencing.

At the time the attack started, morning prayers were underway at the university mosque, where students were not attacked, he said. A mortuary attendant in the town of Garissa says at least 15 people have been killed and at some 60 were injured. The attendant saw the casualties arrive by ambulance. He spoke on condition of anonymity because he was not authorised to speak to the press. Some of the more serious wounded were being flown to Nairobi, the capital, authorities said.

Read: 'Unknown number' of hostages in Kenya university attack: Red Cross

The National Disaster Operations Centre said on Twitter that three of four dorms have been evacuated, with the gunmen cornered in one dorm. No further details were immediately available and Kenya Defence Forces have surrounded the area, journalists said, impeding their access.

Terrified students streamed out of buildings, some young men shirtless, as arriving police officers hunkered down, taking cover. The gunmen had opened fire at guards, triggering a "fierce shootout" with police guarding student dorms, Kenya's National Police Service said in a written statement. The attackers managed to get into the dorms of Garissa University College, raising the possibility of hostage-taking.

Kenya's National Disaster Operations Centre said 29 people wounded during the attack have been admitted to a local hospital, four of them in critical condition. Most have gunshot wounds, the centre said. Police and military surrounded the buildings and were trying to secure the area, police officer Musa Yego told AP.