A fourth bomb reportedly failed to explode at a luxury hotel in Sri Lanka because of a faulty suicide vest.
According to the The Times, the bomber, named as former Kingston University student Abdul Lathief Jameel Mohamed, failed to blow up the explosive at his intended target of the five-star Taj Samudra hotel.
The paper cites an intelligence source who told them that Mohamed retreated to a safe house in Colombo where the device was repaired and later used at a guesthouse close to Colombo zoo, killing two people.
The source said that the death toll would’ve been far higher had it gone off at its intended target.
Mohamed is understood to have studied in the southeast of England at some point between 2006 and 2007 - and later did a postgraduate course in Australia, before returning to settle in Sri Lanka.
His identity was reported after officials in Sri Lanka claimed one of the suicide bombers may have studied in the UK.
Many of the attackers came from well-educated, middle-class families, and had been part of a pair of little-known extremist Muslim groups, Sri Lanka's junior defence minister Ruwan Wijewardene told reporters.
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He added at least one had a law degree and some may have studied in the UK and Australia.
Scotland Yard and a UK Government spokesman declined to comment.
Following the deaths of at least 359 people in the deadly attacks, Sri Lanka's president has asked for the resignations of the defence secretary and national police chief.
The move marks a dramatic internal shake-up after security forces shrugged off intelligence reports warning of possible attacks.
It was not immediately clear who would be replacing them, but President Maithripala Sirisena said during a televised speech that he planned to change the head of the defence forces within 24 hours.
The Islamic State group has claimed responsibility for the attacks, which struck Christians worshipping in three churches and people at three luxury hotels.
Authorities remain unsure of its involvement, though many suspect experienced foreign militants were advising, funding or guiding the attackers.