The explosions at three churches and three hotels in Sri Lanka that killed worshippers and hotel guests also collapsed ceilings and blew out windows.
People were seen carrying victims out of blood-spattered pews. Witnesses described powerful blasts, followed by scenes of smoke, blood, broken glass, alarms going off and victims screaming.
"People were being dragged out," said Bhanuka Harischandra, of Colombo, a 24-year-old founder of a tech marketing company who was going to the city's Shangri-La Hotel for a meeting when it was bombed on Sunday.
"People didn't know what was going on. It was panic mode."
He added, "There was blood everywhere."
Most of the more than 200 killed were Sri Lankans. But the three hotels and one of the churches, St Anthony's Shrine, are frequented by foreign tourists, and Sri Lanka's foreign ministry said the bodies of at least 27 foreigners from a variety of countries were recovered.
The US said "several" American were among the dead while Britain and China said they, too, lost citizens.
The scale of the bloodshed recalled the worst days of Sri Lanka's 26-year civil war, in which the Tamil Tigers, a rebel group from the ethnic Tamil minority, sought independence from the Buddhist-majority country.
During the war, the Tigers and other rebels carried out a multitude of bombings. The Tamils are Hindu, Muslim and Christian.
Local TV showed the Shangri-La's second-floor restaurant was gutted, with the ceiling and windows blown out. Loose wires hung and tables were overturned in the blackened space.
From outside the police cordon, three bodies could be seen covered in white sheets.
Foreign tourists hurriedly took to their mobilep hones to text family and loved ones around the world that they were OK.
One group was on a 15-day tour of the tropical island country, seeing such sites as Buddhist monuments, tea plantations, jungle eco-lodges and sandy beaches.
The tour started last week in Negombo, where one of the blasts took place, and was supposed to end in Colombo, but that may be dropped from the itinerary.
"Having experienced the open and welcoming Sri Lanka during my last week travelling through the country, I had a sense that the country was turning the corner, and in particular those in the tourism industry were hopeful for the future," said Peter Kelson, a technology manager from Sydney.
"Apart from the tragedy of the immediate victims of the bombings, I worry that these terrible events will set the country back significantly," he said.
Harischandra, who witnessed the attack at the Shangri-La Hotel, said there was "a lot of tension" after the bombings, but added: "We've been through these kinds of situations before."
He said Sri Lankans are "an amazing bunch" and noted that his social media feed was flooded with photos of people standing in long lines to give blood.
Australian Associated Press