The Sunday blasts were the worst violence to hit the island since its devastating civil war ended a decade ago.
The horrific death toll, which has risen dramatically overnight, was given on Monday morning by a police spokesman, who said a further 500 people had been wounded.
The news came hours after it was revealed that an improvised bomb discovered at the main airport in Colombo had been defused.
At least three churches, three luxury hotels and a guesthouse were among the targets of the attacks.
"But keeping in view the troubled history of this South Asian nation, as well as the ongoing political tensions, one can identify some potential groups that could be responsible for the blasts", Siegfried O. Wolf, a South Asia expert at the Brussels-based South Asia Democratic Forum, told DW on Sunday.
"The acts of violence against churches and hotels in Sri Lanka are truly appalling, and my deepest sympathies go out to all of those affected at this tragic time". Two people holding both British and USA passports were also among the fatalities.
At least 32 foreigners were among those killed.
Israel's Foreign Ministry said it was not aware of any Israeli victims in the attacks, according to Times of Israel.
Hours later, two more explosions occurred - a blast at a guesthouse in Dehiwala killed two and an eighth incident occurred in Dematagoda on the outskirts of Colombo. From outside the police cordon, several bodies could be seen covered in white sheets.
The floor was littered with a mixture of roof tiles, splintered wood and blood.
One Chinese national was killed during the attacks on Sri Lankan churches and hotels on Sunday, Chinese state newspaper People's Daily said.
The NTJ is a radical Muslim group in Sri Lanka that was linked previous year to the vandalisation of Buddhist statues.
Just over 6 percent of Sri Lanka's population of 21.5 million self-identify as Catholics, with the vast majority of the country being Buddhists.
Ranil Wickremesinghe, Sri Lanka's prime minister, condemned what he called "the cowardly attacks on our people today" and urged the country to remain "united and strong".
On Twitter, Harsha de Silva, a member of Parliament, said there were "many casualties including foreigners".
In Negombo, St. Sebastian's Church was hit during mass.
Alex Agileson, who was in the vicinity, said buildings in the surrounding area shook with the blast.
Police spokesperson SP Ruwan Gunasekara said two explosions were reported from St. Anthony's Church in Kochchikade in capital Colombo and another church in Katana on the outskirts of the capital; a third explosion was reported from a church in Batticaloa in the east.