NAIROBI, Kenya (AP) — Suspected al-Shabab gunmen killed at least six people when they shot at two buses traveling in Mandera County in northern Kenya, a Kenyan official said Friday.
The attack comes a day after the U.S. government issued a travel warning saying that "terrorist attacks involving shootings, grenades, or other explosive devices have occurred, killing and injuring many."
The statement advises U.S. citizens to avoid going to Kenya's border with Somalia including Mandera, Wajir and Garissa counties, the coastal counties of Tana River and Lamu and Nairobi's Eastleigh neighborhood. The warning also advised U.S. citizens to avoid visiting the coastal city of Mombasa's Old Town at night.
Several people were wounded in Friday's attack as the buses headed toward Mandera town at 10 a.m., North Eastern Regional Security Coordinator Mohammed Saleh said. The buses were carrying nearly 90 passengers from the capital, Nairobi.
Last week five police officers were killed in the same area in an attack blamed on the Somalia-based al-Shabab extremist group. Al-Shabab has vowed retribution on Kenya for sending troops to Somalia since 2011 to fight the militants who are waging an insurgency against Somalia's weak western-backed government.
Kenyan security forces have managed to stop most of al-Shabab's attacks in major cities in Kenya that have killed hundreds. Kenya's police force, though, has been heavily criticized for human rights abuses including torture, extrajudicial executions and disappearances of suspects.
However Mandera County, which borders Somalia, remains a volatile area. Al-Shabab militants hijacked a bus in Mandera on November 22, 2014, and killed 28 non-Muslims on board. In December 2014 they killed 36 quarry workers in Mandera town.