Kenya said on Sunday its troops had killed dozens of Shebab Islamists in raids inside Somalia after the execution of 28 non-Muslim people on a Kenyan bus.
There was no independent confirmation of the strikes in response to Saturday's attack by the Al-Qaeda-linked group near Mandera, a northeastern town near the Kenya-Somali border.
Nairobi claimed there were 100 dead in Saturday's operation but gave no further details about where it took place.
"Following the Mandera bus attack, our security forces swiftly initiated a response. They identified, followed and struck the perpetrators of these heinous crimes," Kenya's Vice-President William Ruto said in a statement.
He said Kenyan troops carried out two successful operations, causing "more than 100 fatalities" as well as destroying four trucks carrying weaponry and smashing the camp where the attack was planned.
Shebab fighters executed the passengers after seizing a bus carrying some 60 people in what they said was revenge for police raids on mosques in the troubled port of Mombasa.
The bus, headed for the capital Nairobi, was ambushed shortly after departing from Mandera in the deadliest attack in months.
Passengers were ordered off the vehicle and the travellers separated by the gunmen into Muslims and non-Muslims.
The groups made up of dozens of militants then forced the non-Muslims to reboard the bus and tried to drive off with them. But the vehicle got stuck, so they executed their prisoners before escaping back into Somalia.
Police this week closed the four mosques in Mombasa, a largely Muslim city unlike much of Kenya where Christians make up 80 percent of the population, on the grounds they had come under the influence of hardliners.
"Any place of worship that wilfully hosts terror platforms disqualifies itself from the sanctity of a place of worship," Ruto said.
Saturday's attack was the deadliest claimed by the Shebab since a string of raids against villages and vehicles in the Lamu region on the Kenyan coast in June and July that left 100 people dead, including 49 in a single massacre in Mpeketoni.
Kenya has suffered a series of attacks since invading Somalia in 2011 to attack the Shebab, later joining an African Union force battling the Islamists.
The Shebab also carried out the September 2013 attack on Nairobi's Westgate shopping mall, killing at least 67 people, as a warning to Kenya to pull its troops out of southern Somalia.
During the Westgate attack, some of the victims were killed after the gunmen weeded out non-Muslims for execution by demanding they recite the Shahada, the Muslim profession of faith.