British police today conducted fresh raids in Manchester and arrested a 25-year-old man in connection with the concert bombing, taking the total number of those in custody over the attack to 12.

A spokesperson for Greater Manchester Police said, "Today, May 28, 2017, officers investigating the attack at the Manchester Arena have executed a warrant at an address in Moss Side. A search is currently on-going."

"Officers have also arrested a 25-year-old man in the Old Trafford area on suspicion of offences contrary to the terrorism act," the spokesperson said.

The total number of arrests related to the attack have gone up to 14. However, the number of persons in custody was 12 after two were released without charge.

Britain's terror threat level was yesterday reduced to 'severe' from 'critical'.

The terror threat level now indicates that an attack remains highly likely rather than imminent.

The Army troops deployed as a result of Operation Temperer will be reduced from Monday night.

Prime Minister Theresa May made this announcement after leading a meeting of the government's emergency committee Cobra.

Investigators believe 22-year-old Manchester-born suicide bomber Salman Abedi, from a family of Libyan origin, acted as part of a terrorist network and their focus had been on intercepting his wider network.

Abedi blew himself up at a concert by pop star Ariana Grande at Manchester Arena last week, killing 22 people and leaving 119 injured. -- PTI