The bodies of 15 people, including six children, have been discovered at the site of a fierce gun battle between soldiers and suspects linked to the Easter Sunday bombings in Sri Lanka, a military spokesman has said.
It comes as extra UK flights have left Sri Lanka this morning to take British tourists home.
The shootout began on Friday night in the coastal town of Sammanthurai, 200 miles from the capital, Colombo, after police tipped off soldiers to a suspected safe house.
Military spokesman Sumith Atapattu said that as troops headed towards the site three explosions were triggered and gunfire began.
"Troops retaliated and raided the safe house where a large cache of explosives had been stored," he said in a statement.
He said the militants were suspected members of the National Towheed Jamaat, which has been blamed for last Sunday's attacks.
A police spokesman said that three suspected suicide bombers were among the 15 dead after the gun battle.
Meanwhile, the military said security forces have recovered explosives, detonators, "suicide kits," military uniforms and Islamic State group flags during the raids.
In the same area, police officers acting on information from intelligence officials have found 150 sticks of blasting gelatin and 100,000 small metal balls used to increase shrapnel in explosions, as well as a van and clothing suspected to have been used by those involved in the Easter attack.
Since the suicide bombings at three churches and four hotels on Easter Sunday, in which more than 250 people were killed, police have been carrying out raids across Sri Lanka to find more details about the perpetrators and their supporters.
Islamic State has claimed responsibility for the attacks and Sri Lankan police are searching for suspects thought to have links with the terror group.
Police have detained at least 76 people, including foreigners from Syria and Egypt, in their investigations so far.
Catholic churches in Sri Lanka cancelled all Sunday Masses until further notice over fears of more attacks.
On Friday, Sri Lanka's prime minister Ranil Wickremesinghe apologised for failing to protect the victims of the bombings.
He wrote on Twitter: "We take collective responsibility and apologise to our fellow citizens for our failure to protect victims of these tragic events.
"We pledge to rebuild our churches, revive our economy, and take all measures to prevent terrorism, with the support of the international community."
:: Blood on the walls and torn-up pews - inside bombed Sri Lanka church
Sri Lankan President Maithripala Sirisena said the country had the ability to "completely control the situation in the next few days".
Sky's Asia correspondent Tom Cheshire, who is in Colombo, said: "That's hardly reassuring, the idea that maybe in the next few days they will have things under control."
Sri Lanka's health ministry revised down its estimated death toll from 359 to 253 on Thursday.
While most of those killed were Sri Lankans, officials say more than 30 foreigners died in the blasts - including eight Britons.
Nine suicide bombers carried out the attacks in seven locations in Colombo, the western city of Negombo and the eastern city of Batticaloa.
A photograph obtained by Sky News showed a suspected suicide bomber who studied in Britain , according to a security source.
After the UK's foreign office advised Britons not to travel to Sri Lanka in the wake of the attacks, travel operator TUI UK will fly all of its customers on holiday in Sri Lanka back home today.
Sky's Asia Correspondent who is Colombo has said that it is still a "tense situation" in Sri Lanka.
He added "even though that security operation is on going, and even though the churches... are being cleaned up, we've seen lots of people from the navy going in, getting hoses out, trying to get rid of the carnage and removing the pews - this isn't done yet."
Meanwhile, police in Sri Lanka are providing patrols to protect Muslims who are fearful of reprisal attacks.