No conditions were imposed on the students who were released after being quizzed in relation to the Manchester bombing, Deputy Foreign Minister Reezal Merican Naina Merican said.

The trio are also in safe condition, said Reezal in a statement issued in his capacity as Umno overseas student bureau chairperson.

"I personally know and have met two of the three students during a programme with Malaysian students in Manchester early this year. 

"I have communicated with all three and am happy to inform that they are in safe condition," he said. 

He, however, did not elaborate on why the students were detained for questioning by the Greater Manchester Police, in investigations into the suicide bombing at Manchester Arena last Monday.

United Kingdom's The Times reported it could be because the bomber, Salman Ramadan Abedi, "may have taken advantage of their hospitality while he was planning his attack".

"It is thought that he may have tried to use it as a place to stay, off the radar of security services," it reported.

Friends of the three students said the students strongly opposed to extremism and terrorism and of good character.

Wisma Putra yesterday said the students were arrested at about 5.40pm. 

Reezal said they were arrested at their rented accommodation at Banff Road, Manchester, which The Times said the students have resided in for four years.

He also urged Malaysian students to keep in close contact with the High Commission in London and to adhere to instructions given by local authorities. 

A total of 22 people, including children, were killed and 116 injured when the British national suicide bomber  detonated a shrapnel-laden improvised explosive device at the exit of the Manchester Arena, after a concert by American singer Ariana Grande.

So far, 16 people have been arrested in connection with the incident. 

British Prime Minister Theresa May raised the UK threat level to "critical" immediately after the attack - the first time since 2007 - but has since reduced it to "severe".

Police spoke of a "network" which likely supported the bomber, of which members are believed to be still at large.