The death toll from the attack on a university has again risen dramatically. Officials now put the number of students killed at almost 150, with many more wounded.

Kenya's national disaster response agency announced via its Twitter account on Thursday that the number of people killed in the attack on Garissa University College, which began more than 12 hours earlier had risen to 147.

In a previous tweet, the agency said that the siege had now ended and that security forces had killed all four gunmen involved in the attack. It also said that plans were underway to evacuate students and other affected persons.

Earlier, Interior Minister Joseph Nkaissery and the national police chief, Joseph Boinet, held a press conference in Garissa, at which Nkaissery put the death toll at 70 and the number of wounded at around 80.

Boinet also announced that as a security precaution, the authorities had imposed a dusk-to-dawn curfew for Garissa as well as the nearby counties of Wajir, Tana River and Mandera, each of which is located near the Somali border.

Fast track for 10,000 new police recruits

Kenyan President Uhuru Kenyatta announced a few hours earlier that he had instructed Chief Boinet to fast-track the recruitment and training of 10,000 new police officers. Speaking in a nationally televised address, President Kenyatta said that Kenya had "suffered unnecessarily due to shortage of security personnel."

The Somalia-based Islamist militant group al-Shabab has claimed responsibility for the attack.

Al-Shabab has pledged to punish Kenya for contributing troops to an African Union force fighting the militants in Somalia. The Islamist group also claimed responsibility for a deadly attack on the Westgate shopping mall in Nairobi in 2013.

pfd/rc (AFP, AP, Reuters)