Sri Lankan-Canadians were gathering Monday to mourn those killed in a massive terrorist attack in their homeland as the Canadian government stepped up cautions for anyone considering visiting the country as it grapples with the fallout from the widespread violence.

At least 290 people were killed and hundreds more injured in a series of co-ordinated bomb blasts that rocked churches and hotels across Sri Lanka on Sunday. Authorities said many of the attacks, believed to be carried out by suicide bombers with a local Islamic group, targeted worshippers gathered to celebrate Easter.

As Sri Lankan government officials wrestled with latest explosions, imposed a curfew on the public and blocked the bulk of social media activity in the country, the Canadian government urged travellers to exercise "a high degree of caution" if visiting the area.

Closer to home, however, Sri Lankans organized vigils from coast to coast to both pay tribute to those killed and seek solace among those who have witnessed violence in their homeland before.

Edward Anura Ferdinand, president of the Sri Lanka Canada Association of Ottawa, said hundreds of Sri Lankans are expected to gather in several cities to light candles, sing hymns and come to terms with the recent bombings. One such vigil will unfold Monday evening on Parliament Hill in Ottawa.

Anura Ferdinand said the horror of Sunday's violence is compounded by the memories it revives, adding many Sri Lankan-Canadians are grappling not only with the latest events but memories of the bloody civil war that drove many of them out of the country in the first place.

"We are in the position of healing our wounds after a 30-year war," he said in an interview. "There was a time when breaking news was a common thing, every now and then you would hear explosions. . . . There are so many bad memories that come to my head personally and so many of the other members when we heard about this."

In the civil war, which came to an end in 2009, a powerful rebel army known as the Tamil Tigers was crushed by the government.

While anti-Muslim bigotry has swept the island in recent years, fed by Buddhist nationalists, the island also has no history of violent Muslim militants. The country's small Christian community has seen only scattered incidents of harassment in recent years.

Sunday's explosions -- centred on the cities of Colombo, Negombo and Batticaloa -- collapsed ceilings and blew out windows, killing worshippers and hotel guests in one scene after another of smoke, soot, blood, broken glass, screams and wailing alarms.

Sri Lanka's health minister said intelligence reports had repeatedly flagged threats of violence, but alleged the warnings went unheeded by government officials.

While no group has officially taken responsibility for the attacks, Rajitha Senaratne attributed the attacks to a group known as National Thowfeek Jamaath. Police said they have arrested 13 people in connection with the bombings.

Late Monday, Sri Lankan Prime Minister Ranil Wickremesinghe gave the military wider berth to detain and arrest suspects -- powers that were used during the civil war but withdrawn when it ended.

For Canadian MP Gary Anandasangaree, who fled Sri Lanka at the age of 10, the move was deeply distressing.

He said Sunday's attacks risk destabilizing a country that's still struggling to establish a fragile peace, adding many of his fellow expatriates are anxious about its longer-term consequences for loved ones back home.

"While peace has not been achieved on the island in the past 10 years, there was some semblance of order in some places," Anandasangaree said. "This just brings everything to a halt."

Anandasangaree has organized a vigil in east Toronto for Monday night, which is due to feature religious leaders from Christian, Buddhist, Jewish and Muslim communities. He said the Easter Sunday bombings are the latest in a line of religiously motivated terrorist attacks around the world and called for Canadians of all faiths to denounce hate and intolerance.

Anura Ferdinand said that while all his family and friends are safe in the wake of the blasts, many other families now based in Canada are mourning the deaths of loved ones.

Officials with Global Affairs Canada said no Canadians were among the 39 foreigners killed in the attacks, but stepped up travel advisories for anyone in or headed to the country.

"The situation remains volatile," reads the advisory, which urges Canadians to exercise a high degree of caution. "Other attacks could occur throughout the country. Local authorities have declared a state of emergency and curfew could be imposed at any time. Local authorities have also temporarily blocked access to some social media.

Spokeswoman Amy Mills urged Canadians in Colombo, the nation's capital, to limit their movements, avoid impacted areas, and take direction from local authorities.

-- With files from the Associated Press