Nairobi - Somalia's al-Qaeda-linked Shabaab 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.
"Our officers responded and the suspected attackers ran away towards Somalia," he said, adding that "no one was killed or wounded."
Shabaab spokesperson Abdulaziz Abu Musab told AFP the gunmen had killed "all the Kenyan soldiers" in a lorry as well as five police officers, and had then stolen two pick-up trucks and taken them across the border to Somalia.
Kenya's army also denied any deaths and called the claim "propaganda."
The ambush is the latest in a wave of attacks in Kenya that authorities have blamed on militants connected to the Shabaab.
On Friday a double bomb attack in a Nairobi market left 10 people dead and scores wounded.
Kenya has been targeted by the Shabaab since sending troops to war-torn Somalia in 2011.
The group has vowed revenge, and claimed a deadly September 2013 attack on Nairobi's Westgate mall.
On Sunday military aircraft thought to be from Kenya pounded Shabaab bases in their stronghold of Jilib in southern Somalia.
The United States on Saturday said it was preparing to cut staff levels at its Nairobi embassy because of the mounting threat of attacks in Kenya by Islamist militants.
Earlier this week Britain, France and Australia also issued updated travel advice for their citizens in Kenya, following a string of grenade attacks.