Sri Lanka’s government has blamed local jihadist group National Thowheed Jamath for one of Asia’s deadliest terrorist attacks in years, and said other nations had shared intelligence ahead of the blasts.

The death toll rose to 290 in the coordinated attacks on Easter Sunday at churches and luxury hotels, which the government said had been carried out by seven suicide bombers. The Easter Sunday assaults targeted foreign tourists and Christians, marking a shift from the violence that fueled a three-decade civil war on the Indian Ocean island.

“There had been several warnings from foreign intelligence agencies about the impending attacks,” Sri Lanka’s Health Minister Rajitha Senaratne said at press conference in Colombo. “Persons named in intelligence reports are among those arrested. Some named in the reports had died during attacks.”

“We don’t see how a small organization can do all of this,” Senaratne added. “We are now investigating international support for the group and their other links.”

Prime Minister Ranil Wickremesinghe said in an address to the nation late Sunday authorities had received warnings but “not enough attention had been paid.” One of his cabinet ministers, Harin Fernando, tweeted an internal police memo dated April 11 warning a group called National Thowheed Jamath planned to bomb Catholic churches and the Indian High Commission.

A sense of unease pervaded the nation on Monday following a period of relative calm in the decade since the end of a brutal conflict between the predominately Buddhist Sinhalese majority and mostly Hindu Tamil minority.

Police recovered 87 low explosive detonators abandoned at a bus stand in the Pettah area of the capital on Monday, according to an emailed statement, while a bomb disposal squad conducted a controlled explosion in the capital after finding explosives in an abandoned vehicle.

U.S. President Donald Trump and other world leaders condemned the attack and offered support. Sri Lanka confirmed that 11 foreigners who died in the attacks had been identified — including citizens of India, Portugal, Turkey, Australia, the U.K. and U.S. — and said 25 unidentified bodies believed to be foreigners were in a Colombo morgue. Most were targeted at the Shangri-La, Kingsbury and Cinnamon Grand hotels in the capital.

Several blasts occurred hours after the first explosions on Sunday, and experts detonated a pipe bomb found on a road near Colombo’s airport. Authorities imposed a nationwide curfew and blocked platforms like Facebook and Whatsapp.

The Colombo Stock Exchange put its Monday opening on hold and schools will remain closed until Wednesday. Sri Lankan Airlines Ltd. advised travelers to arrive four hours before their flights to undergo additional security checks.

Test for Government

The attacks will test a government that’s reeling from a political crisis last year that has weighed on the economy and led to downgrades in Sri Lanka’s credit rating.

“What these bombings potentially do is take it from inertia and political infighting and rudderlessness to a real fear of instability and a sense of a return to the bad old days,” said Alan Keenan, a senior Sri Lanka analyst with the International Crisis Group based in London. “It’s striking that in almost three decades of war between the Tamils and government forces, foreign tourists were never targeted.”

Catholics, split between the Sinhalese and Tamils, make up 6.5 percent of Sri Lanka’s population, according to the nation’s 2012 census. Buddhists account for 70 percent of the total, while Hindus and Muslims make up the rest.

In the early 1980s, the Liberation Tigers of Tamil Eelam — known as the Tamil Tigers — began fighting for an independent homeland in the north and east of Sri Lanka. The conflict, marked by the use of child soldiers and human-rights violations on both sides, killed more than 100,000 people before former strongman Mahinda Rajapaksa’s government won a decisive victory in 2009.

Political Tensions

Rajapaksa has been a key player in Sri Lanka’s political fighting over the past six months. Last October, he was suddenly appointed prime minister by President Maithripala Sirisena, leading to a constitutional crisis. Wickremesinghe, the deposed prime minister, was reinstated in December after a Supreme Court decision.

“It is absolutely barbaric to see such violent attacks on such a holy day. Whoever is behind these attacks must be dealt with immediately,” Rajapaksa tweeted. “We will not tolerate such violence, such acts of terrorism, of cowardice within our borders once again.”

It remains to be seen whether Sri Lanka’s politicians will unite in the face of the attacks, which threaten to further hurt economic growth. Wickremesinghe warned that tourism would suffer and investors may pull money from the country.

‘Bad News’

Sri Lanka’s economy has struggled in recent years, forcing the government to take out a $1.5 billion loan from the International Monetary Fund. Economic growth in the quarter to December was the slowest in 19 quarters. The rupee dropped to consecutive record lows last year amid the political crisis, before recovering this year.

“That is bad news for the country where the memories of the civil war are still very much alive,” said Raffaele Bertoni, head of debt-capital markets at Gulf Investment Corp. in Kuwait City. “Tourism is a very important sector for the economy and one of the major source of external reserves.”

Sri Lanka has a history of communal violence between virtually all groups, according to Keenan from Crisis Group.

“What’s surprising about this is the particularly brutal and coordinated nature of the attacks and targets, this combination of what appear to be Tamil Catholic churches and high-end hotels,” he said. “These are the first classically terrorist attacks since the end of the war.”