Kenya security chiefs ousted after massacre........

Kenya's interior minister and police chief have been removed from their posts, hours after Somalia's Shabab rebels carried out a fresh massacre.

In a televised address to the nation on Tuesday, President Uhuru Kenyatta also vowed his security forces will "intensify the war on terrorism" after a spate of killings in the country by the al-Qaeda-affiliated insurgents.

A group of Shabab rebels stormed into a quarry near the border town of Mandera shortly after midnight, and police and officials said they weeded out non-Muslims and shot them in the head, while some of the victims were also beheaded.

The Shabab said in a statement that their latest cross-border attack was fresh retaliation for Kenya's 2011 invasion and continued presence in Somalia, as well as its treatment of Muslims in the troubled port city of Mombasa.

The attack came a week after the rebels executed 28 people who were grabbed from a bus travelling from Mandera, a border town located on the frontier between Kenya, Somalia and Ethiopia, and the group vowed to conduct more "uncompromising, relentless and ruthless" attacks.

Kenyatta, however, vowed Kenyan troops would stay put in Somalia, where they are now part of an African Union forces battling the Shabab and supporting the war-torn country's internationally-backed government.

"This is a war and a war that we must win, we must win it together," he said, calling the Shabab "deranged animals" who had killed more than 800 people in attacks inside Kenya, including 500 civilians and 300 security officers.

"We will not flinch or relent in the war against terrorism in our country and our region. We shall continue to inflict painful casualties on these terrorists until we secure our country and region."

The Kenyan government has been under fire since last year's attack by the Shabab against the Westgate shopping mall in Nairobi, in which at least 67 people were killed in a siege involving just four gunmen and that lasted four days.

The sacked interior minister, Joseph Ole Lenku, has become a figure of public ridicule for his statements on the security situation, while national police chief David Kimaiyo has been accused of repeated lapses - contributing to dwindling public confidence in the country's security apparatus.