Nairobi's hospital treated more than a hundred students injured in a stampede just before dawn on 12 April, caused by fear of another attack by al-Shabaab militants when an electrical transformer accidentally blew up. One of them died and several suffered serious injuries after they jumped out of windows in a panic.

The stampede underlined growing tensions just over a week after gunmen stormed another university campus in Garissa. The dead student was among others who jumped from residence halls as high as five floors up.

Witnesses said the transformer blew up at about 4.30am, setting off terrified screams from the women's wing of a dormitory. The panic spread to the men's wing, where students woke up and scrambled to get out.

They said the transformer went out in three loud blasts, plunging the dormitory into darkness, which heightened the panic among the students.

Kenya responded to the latest attack with air strikes on al Shabaab targets in Somalia and the closure of informal financial firms suspected of involvement in the funding of the militants.

It has also said the United Nations refugee agency should relocate hundreds of thousands of Somali refugees sheltering in the Dadaab camp in the remote north eastern region.