Somali militants burst into a university in eastern Kenya on Thursday and killed nearly 150 students in the worst terrorist attack since the 1998 bombing of the United States Embassy here, laying bare the nation’s continuing vulnerability after years of battling Islamist extremism.

A small group of militants, most likely between four and 10, roved from dorm to dorm, separating Christian from Muslim students and killing the Christians, the authorities said. Students described being awakened before dawn by the sound of gunfire and fleeing for their lives as masked attackers closed in.

Officials said that by the time Kenyan commandos cornered and killed the attackers on an upper floor, 147 people lay dead.

Despite new security laws, significant Western help and a heightened state of vigilance that has already put police officers on almost every major street corner in the capital, Nairobi, Kenya remains squarely in the cross hairs of the Shabab, the Somali terrorist group that immediately claimed responsibility for the attack on Thursday.

The Shabab has killed hundreds of Kenyans - on country buses, in churches, in remote coastal towns and inside one of Kenya’s fanciest malls during a devastating siege in 2013 that left 67 people dead and rattled Kenya’s prized image as a cornerstone of stability in this part of Africa. The Kenyan government is so desperate to stop the Shabab, one of the most violent franchises of Al Qaeda, that some officials have even proposed building a 424-mile walk across the entire Somali border.

- Manohar