(ABC NEWS) – Three arrests have been made in connection with Monday’s deadly explosion in Manchester that killed 22 people and injured more than 60 others at one of Europe’s largest and most well-known arenas, U.K. authorities said Wednesday.
The suspects were apprehended in south Manchester early Wednesday morning, according to the Greater Manchester Police.
Police previously announced that they had arrested a 23-year-old man on Tuesday in connection with the attack, which ISIS has claimed responsibility for.
The arrests announcement came a day after U.K. Prime Minister Theresa May increased the country’s threat level to critical — the highest of the U.K.’s five threat levels — indicating that another attack could be imminent.
Monday’s explosion, which occurred in the Manchester Arena’s foyer after an Ariana Grande concert ended, killed 22 people and injured 64 others. Several children were seriously injured in the attack, and an eight-year old and a 15-year-old were among the dead.
Authorities on Tuesday identified Salman Abedi, 22, as the suspected suicide bomber behind the fatal explosion, but they are still trying to determine if he acted as a part of a group. Speaking to the BBC Radio on Wednesday, U.K. Home Secretary Amber Rudd indicated that she thought it was a strong possibility.
Separately on Wednesday, the Metropolitan Police Service said that the public should expect to “see more armed officers” patrolling the streets in response to the elevated terrorist threat levels.
“The public will see more armed officers, working alongside their neighborhood and specialist colleagues on proactive operations and targeted patrols, both on foot and in vehicles,” MPS said in a statement early on Wednesday.
The service said it would “continually change” the number of officers deployed as well as the officer’s posts and tactics in an attempt to avoid predictability.
“The reality is that we must be prepared to be able to respond to and deal with armed and deadly attackers, so we must be in a position to respond with firearms officers who will use force to stop those attackers in their aim,” MPS Commander Jane Connors said in the statement. “That is why is we have increased the number of firearms who are on duty, both out walking and in roaming patrols, at fixed points and carrying out a range of operations.”
Amid the security developments, the Ministry of Defense announced that the Changing the Guard ceremony at Buckingham Palace had been canceled for Wednesday in order to allow police officers to be redeployed.
The Manchester Islamic Center and Didsbury Mosque, which Abedi had been know to attend, issued a statement earlier Wednesday condemning the attack.
“The thoughts and prayers of Manchester Islamic Center is with the victims, their families, their friends and the Manchester community as a whole,” the statement read.
In the past, Abedi had attended with his family, but it was unclear how regularly he attended as of recently.
ABC News’ Aicha Hammer contributed to this report.