There was no claim of responsibility for the Easter Sunday attacks on two churches and four hotels in and around Colombo, the capital of predominantly Buddhist Sri Lanka, and a third church on the South Asian nation's northeast coast.
Four of the bombs went off at roughly the same time, at 8.45 a.m., with the other two coming within 20 minutes.
Sri Lankans accounted for the bulk of the dead and wounded although government officials said 32 foreigners were killed, including British, U.S., Turkish, Indian, Chinese, Danish, Dutch and Portuguese nationals.
President Maithripala Sirisena, who was abroad when the attacks happened, had called a meeting of the National Security Council early on April 22, a government source said. Prime Minister Ranil Wickremesinghe would attend the meeting, the source said.
The Sri Lankan military, who were clearing the route from Colombo airport late on April 21 in preparation for Sirisena's return, found a crude bomb near the departure gate, an air force spokesman said.
They destroyed the device in a controlled explosion.
There were fears the attacks could spark a renewal of communal violence, with police also reporting late on April 21 there had been a petrol bomb attack on a mosque in the northwest and arson attacks on two shops owned by Muslims in the west.
Sri Lanka was at war for decades with ethnic minority Tamil separatists but violence had largely ended since the government victory in the civil war, 10 years ago.
Sri Lanka's 22 million people include Christian, Muslim and Hindu populations of between about eight and 12 percent.
Security forces raided a house in Colombo on April 21 afternoon, several hours after the attack. Police reported an explosion at the house and said three officers were killed.
Police said on Sunday 24 people had been arrested, all of whom were Sri Lankan.
The US State Department issued a revised travel warning that said terrorist groups were continuing to plot.
"Terrorists may attack with little or no warning," it said in the warning, which was set at two on a scale on which four means do not travel.
Possible targets included tourist spots, transport hubs, shopping malls, hotels, places of worship, airports and other public areas, it said.
The island-wide curfew was lifted early on April 22, although there was uncharacteristically thin traffic in the normally bustling capital.
Soldiers with automatic weapons stood guard outside major hotels and the World Trade Centre in the business district, where the four hotels were targeted on April 21, according to a Reuters witness.
Scores of people who were stranded overnight at the main airport began making their way home as restrictions were lifted.
The government also blocked access to social media and messaging sites, including Facebook and WhatsApp, making information hard to gather.
Wickremsinghe acknowledged on April 21 that the government had some prior information about possible attacks on churches involving a little-known Islamist group but said ministers had not been told.
