Nairobi: Gunmen attacked Garissa University College on Thursday, shooting indiscriminately in campus hostels, killing at least two people and wounding four others, police said.

Police and military surrounded the buildings and were trying to secure the area in eastern Kenya, police officer Musa Yego said.

Kenya's National Police Service said in a written statement that armed attackers forced their way onto the campus by shooting at guards, triggering a "fierce shootout" with police guarding student hostels.

However the attackers managed to get into the hostels. The statement, which did not mention a death toll, said police and members of other security agencies were "engaged in an elaborate process of flushing out the gunmen from the hostels."

Kenya's northern and eastern regions, which are near the Somali border, have suffered many attacks blamed on al-Qaeda-linked Somali Islamist group, al-Shabab.

Al-Shabab has vowed retribution on Kenya for sending troops into Somalia to fight the terrorists. Kenya sent its troops there in 2011 to fight al-Shabab terrorists following cross-border attacks.

In February, al-Shabab claimed responsibility for attacks in the county of Mandera on the Somali border in which twelve people died. Four of them died in an attack on the convoy of Mandera County Governor Ali Roba.

Al-Shabab carried out large-scale attacks in Mandera last year. The militants hijacked a bus and singled out 28 non-Muslims forcing them to lie on the ground before shooting them dead. Ten days later, 36 non-Muslim quarry workers were killed by the extremists.

Police statistics show that 312 people have been killed in al-Shabab attacks in Kenya from 2012 to 2014. Thirty-eight people were killed and 149 wounded in Garissa in the same period, according to police statistics.