Somalia's al-Qaida-linked Shebab said it had attacked an army convoy across the border in Kenya on Monday and killed several soldiers, but Kenya's army denied it suffered any casualties.

The convoy was attacked in the restive Mandera region of northeast Kenya near the Somali border, local police chief Noah Mwivanda said.

The United States said Saturday it was preparing cut staff levels at its Nairobi embassy because of the mounting threat of attacks in Kenya by Islamist militants.

A statement from the U.S. ambassador to Kenya, Robert F. Godec, said the embassy was "continuously reviewing and updating its security measures, and expects to take additional steps in coming days, to include on U.S. staffing."

Ten people were killed and over 70 wounded Friday in two bomb attacks in a busy market in the Kenyan capital Nairobi, the latest in a wave of unrest blamed on Islamist militants.

The twin bombings came as hundreds of British tourists were being evacuated from beach resorts near the port city of Mombasa after Britain's Foreign Office and other nations issued new travel warnings.

Hundreds of British tourists are being evacuated from beach resorts near Kenya's coastal city of Mombasa following new warnings of terror attacks, officials and tour operators said Friday.

Special charter flights were organized days after Britain, France, Australia and the United States issued new travel warnings for Kenya's coast following a wave of attacks and unrest linked to Islamist extremists.

Kenya's foreign ministry accused several foreign nations of "unfriendly acts" Thursday, after they issued travel warnings for coastal regions following a wave of attacks and unrest linked to Islamist extremists.

The advice from Britain, France and Australia to their nationals to avoid the coastal city of Mombasa dealt a fresh blow to Kenya's already embattled tourism sector, as avoiding the port complicates travel to nearby beach resorts.

At least two people were killed and dozens more wounded when bombs exploded in two buses on a busy highway in the Kenyan capital Nairobi, officials said.

The bombings came just a day after twin attacks in the restive port city of Mombasa, including a grenade attack on a bus, which killed four, and a bombing outside a luxury beach hotel.

At least three people were killed and several others wounded Saturday in twin attacks in Kenya's restive coastal city of Mombasa, officials said.

One blast occurred in the busy Mwembe Tayari area of the city center, and the other close to a well-known beach hotel, the Reef Hotel, in the Nyali area of the city.

U.S. Secretary of State John Kerry left late Tuesday on his first major tour of Africa focused on some of the continent's most brutal wars including the bloodshed in South Sudan. 

The trip, which will take in Ethiopia, the Democratic Republic of Congo and Angola, will seek to "encourage democratic development, promote respect for human rights, advance peace and security," State Department spokeswoman Jen Psaki has said.

Somalia has temporarily recalled its ambassador to Kenya following the arrest and alleged harassment of one of its diplomats in Nairobi, officials said Monday.

The diplomatic protest comes amid an ongoing crackdown in Kenya against suspected Islamist militants that has also seen thousands of Somalis and ethnic Somalis detained by Kenyan police and dozens of them deported.

At least four people, including two policemen, were killed on Wednesday when a car bomb exploded outside a police station in Nairobi near a major Somali neighborhood, Kenya's government said.

"At least four dead after a sedan exploded at Pangani police station, of which two are police officers," the interior ministry tweeted.