Media playback is unsupported on your device Media caption Volunteers provide water, food and support to those mourning the bombing

One of the attackers behind the Easter Sunday bombings in Sri Lanka once studied in the UK, officials say, as further details on the bombers emerge.

He visited south-east England in 2006-7 to study but did not complete a full university degree, a senior Whitehall official told the BBC.

The attacker later did a course in Australia, Sri Lanka's deputy defence minister said.

The death toll has risen to 359, with more than 500 people wounded.

Prime Minister Ranil Wickremesinghe has said the Islamic State (IS) group may be linked to the blasts.

IS has said it carried out the attacks, which targeted churches and high-end hotels, although it did not provide direct evidence of its involvement.

In another development, Sri Lankan President Maithripala Sirisena replaced Defence Secretary Hemasiri Fernando and took steps to sack the Inspector General of Police, Pujith Jayasundara.

Key information from officials today:

Police have identified eight out of nine attackers - one of whom was a woman - with no foreigners among them

Most of the attackers were "well educated" and "middle class"

The US envoy to Sri Lanka warned there were "ongoing terrorist plots" in the country

Police have now detained around 60 people in connection with the attacks

Media playback is unsupported on your device Media caption Hero Ramesh was killed in the blast in Batticaloa

What do we know about the attackers?

A Whitehall official confirmed the name of the bomber who had visited the UK as Abdul Latif Jamil Mohammed.

Sri Lankan Deputy Defence Minister Ruwan Wijewardene said the attacker had gone on to do "his postgraduate in Australia before coming back to settle in Sri Lanka".

Confirmation that he studied in the UK in the mid-2000s would tend to cast doubt on the likelihood of his being radicalised so long ago, says the BBC's Security Correspondent Frank Gardner.

Media playback is unsupported on your device Media caption The footage shows a man wearing a large backpack calmly walking towards St Sebastian's church

It also points to his being in his early to mid-30s at the time of the attacks, our correspondent adds.

Mr Wijewardene added that most of the attackers had been "well educated and come from... middle or upper middle class" families.

"They are financially quite independent and their families are quite stable financially," he said.

Two of the bombers are reportedly brothers and the sons of a wealthy Colombo spice trader. They detonated their explosives at the Shangri-La and the Cinnamon Grand hotels, police sources told the AFP news agency.

From privilege to terror

Analysis by the BBC's Security Correspondent Frank Gardner

The announcement that most of the attackers were "well educated" and "middle class" is not as surprising as it sounds.

Although poverty and lack of opportunities have steered many down a path to terrorism, there are also numerous examples of individuals abandoning a relatively comfortable lifestyle for a violent cause.

Ziad Jarrah, one of the 9/11 attackers who hijacked United Airlines flight 93, came from a privileged Lebanese family. More recently, there have been cases of British jihadists who have worked for the NHS, including doctors.

The late IS executioner Mohammed Emwazi, aka "Jihadi John", attended the University of Westminster in London. And the original co-founder of al-Qaeda, Osama Bin Laden, chose to leave behind a luxurious life in Jeddah to go and fight the Soviets in Afghanistan during the 1980s.

Sri Lanka's government has blamed the blasts on local Islamist group National Thowheed Jamath (NTJ) but Mr Wickremesinghe said the attacks "could not have been done just locally".

"There had been training given and a co-ordination which we are not seeing earlier," he said.

Police have now detained around 60 suspects in connection with the attack. A state of emergency remains in effect to prevent further attacks.

The nearly simultaneous attacks targeted three churches packed for Easter services and three major hotels in the capital, Colombo.

Image copyright Getty Images Image caption There were emotional scenes outside St Anthony's Shrine in Colombo

An attack on a fourth hotel on Sunday was foiled, Mr Wickremesinghe said. He also warned that further militants and explosives could still be "out there" following the attack.

One of the targeted hotels, the Kingsbury, has now reopened.

The country remains tense with police still looking for suspects and possible further explosives.

Two controlled explosions of suspect packages were carried out on Wednesday, including one near a popular cinema in Colombo.

Cautioning about "ongoing terrorist plots in the country", US envoy to Sri Lanka Alaina Teplitz told reporters that terrorists could "strike without warning".

Who could be behind the attacks?

IS said online that it had "targeted nationals of the crusader alliance [anti-IS US-led coalition] and Christians in Sri Lanka".

It provided no evidence for the claim but shared an image on social media of eight men purported to be behind the attack.

The group's last territory fell in March, but even then experts had warned it does not mean the end of IS or its ideology.

Mr Wijewardene has also told parliament that NTJ was linked to another radical Islamist group he named as JMI. He gave no further details.

He also said "preliminary investigations" indicated that the bombings were in retaliation for deadly attacks on mosques in Christchurch, New Zealand, in March.

NTJ has no history of large-scale attacks but came to prominence last year when it was blamed for damaging Buddhist statues. The group has not said it carried out Sunday's bombings.

The Sri Lankan government is facing scrutiny after it emerged the authorities were warned about a possible attack.

Security services had been monitoring the NTJ but the prime minister and the cabinet were not warned, ministers said.

On Tuesday, President Sirisena promised "stern action" over the failure to pass on the warnings and said he would restructure the country's police and security services.

Who were the victims?

The first mass funeral was held on Tuesday, as Sri Lanka marked an official day of mourning for the victims.

Most of those who died were Sri Lankan nationals, including scores of Christians attending Easter Sunday church services.

Some 38 foreign nationals were among the dead, with another 14 unaccounted for. The death toll includes at least eight British citizens and at least 11 Indian nationals.

The mass funeral for about 30 victims took place at St Sebastian's church in Negombo, north of Colombo, which was one of the places targeted in Sunday's blasts. Another funeral service was scheduled for later on Tuesday.

A moment of silence was also observed at 08:30 on Tuesday, reflecting the time the first of six bombs detonated.