In an update, officials said no fewer than 35 foreigners, including Americans, Britons and Dutch, died when a string of coordinated bombings hit high-end hotels and churches in and around the Sri Lankan capital of Colombo on Sunday during Easter services.

Police have revised the death toll upwards, from 137 to 156.

The coordinated blasts took place at 8:45 a.m. local time.

Foreigners were among the dead in Colombo, Sri Lanka Health Services director general Anil Jasinghe said

At least six explosions have been reported. Three churches in Colombo, Negombo and Batticaloa were targeted during Easter services.

At least 400 people were injured and were undergoing treatment, an employee at the National Hospital of Sri Lanka said by phone.

Sri Lanka’s police chief made a nationwide alert 10 days before Sunday’s bomb attacks in the country that suicide bombers planned to hit “prominent churches”, according to the warning seen by AFP.

Police chief Pujuth Jayasundara sent an intelligence warning to top officers on April 11 setting out the threat.

“A foreign intelligence agency has reported that the NTJ (National Thowheeth Jama’ath) is planning to carry out suicide attacks targeting prominent churches as well as the Indian high commission in Colombo,” said the alert.

The NTJ is a radical Muslim group in Sri Lanka that came to notice last year when it was linked to the vandalization of Buddhist statues.

Sri Lanka’s Prime Minister Ranil Wickremesinghe condemned the string of blasts that killed at least 137 people on Sunday as “cowardly” and said the government was working to “contain the situation.”

“I strongly condemn the cowardly attacks on our people today,” he said in a tweet from his verified account.

“I call upon all Sri Lankans during this tragic time to remain united and strong The government is taking immediate steps to contain this situation.”

“Emergency meeting called in a few minutes. Rescue operations underway,” Sri Lanka’s Minister of Economic Reforms and Public Distribution, Harsha de Silva, said in a tweet on his verified account.

He said he had been to two of the attacked hotels and was at the scene at St Anthony’s Shrine and described “horrible scenes.”