COLOMBO • Sri Lanka's Catholic churches suspended all public services over security fears yesterday, as thousands of troops joined the hunt for suspects in the deadly Easter bombings that killed nearly 360 people.
Officials said privately that the authorities were trying to find at least one person believed to be armed with explosives.
A letter distributed to security officials said there was "credible information" that National Thowheeth Jama'ath (NTJ), the radical Islamist group thought to have carried out the bombings on Sunday, was planning another attack "specifically targeting Sufi shrines".
Several officials confirmed the authenticity of the letter and Prime Minister Ranil Wickremesinghe said in more general terms that the security services were hunting for people believed to be planning more attacks.
Overnight, security forces using newly granted powers under the country's state of emergency arrested 16 more suspects in connection with the attacks. Police have so far arrested 75 people, but tensions remain high, with several suspects unaccounted for.
Recriminations have flown since suicide bombers blew themselves up in luxury hotels and churches packed with Easter worshippers amid allegations that specific intelligence about the plot was ignored.
The country's top defence ministry official quit yesterday, taking responsibility for the security failures that led to the suicide bombings. Mr Hemasiri Fernando, the most senior bureaucrat at the ministry, sent a letter of resignation to President Maithripala Sirisena, the official said.
Mr Sirisena has also asked the police chief to resign, though he has not done so yet.
A senior Catholic priest said all public services were being suspended, and all churches closed "on the advice of security forces". Private services for burials will still be carried out, but no public masses are scheduled.
Brigadier Sumith Atapattu said the army has increased its deployment by 1,300 to 6,300, with the navy and air force also deploying 2,000 more personnel. The authorities also announced a ban on drone flights and suspended licences issued to commercial operators.
Yesterday, Mr Sirisena, who is also Defence and Law and Order Minister, met the country's political parties to discuss the crisis, and was also expected to meet religious leaders as concerns rose over a potential backlash against the Muslim minority.
Investigators are still piecing together information about the attacks and those involved.
An FBI team from the United States is now in Sri Lanka, and Britain, Australia and the United Arab Emirates have also offered intelligence help. Experts said the bombings bear many of the hallmarks of Islamic State in Iraq and Syria (ISIS) attacks, and the government has suggested local militants could not have acted alone. But it has not officially confirmed any ISIS role in the blasts.
A key suspect also remains unaccounted for: NTJ leader Zaharan Hashim. He appears to be among eight people in a video released on Tuesday by ISIS, after it claimed responsibility for the attacks, and seen leading a pledge of allegiance to ISIS chief Abu Bakr al-Baghdadi.
Officials said it was unclear if Hashim was among the suicide attackers or escaped after the blasts.
In all, nine people were believed to have blown themselves up on Sunday, either during attacks or when police attempted to arrest them.
Yesterday, the Sri Lankan government said it was suspending plans to grant citizens of 39 countries visa-free entry during the country's tourism low season after the deadly attacks.
"Investigations have revealed foreign links to the (Easter) attacks and we don't want this programme to be abused," Tourism Minister John Amaratunga said.
AGENCE FRANCE-PRESSE, NYTIMES