UK police arrest two more in hunt for suicide bomber's network

British police said they had arrested two men on Saturday as they stepped up their efforts to capture a suspected network behind the suicide bomber who killed 22 people in Manchester earlier this week.

The arrests were among a total of 13 that have been made in recent days.

Officers used a controlled explosion to gain entry to the address in the north of the city where the latest arrests were made. Detectives are now questioning 11 men over the attack by Salman Abedi at a pop concert in Manchester on Monday.

Earlier, a 44-year-old man was arrested in connection with the suicide attack on a concert in Manchester.

According to Metropolitan Police Assistant Commissioner Mark Rowley, "immense" progress had been made in the investigation into Salman Abedi, who killed 22 people, seven of them children, at a pop concert in Manchester on May 22.

"They're very significant, these arrests. We're very happy we've got our hands around some of the key players that we are concerned about. But as I say, there is still a little bit more to do," Rowley told broadcasters.

Since the attack, police backed up by the army have been patrolling cities and trains. The interior minister, Amber Rudd, said the official threat risk remained at its highest level, "critical", meaning another attack is expected imminently.

Hospitals have been warned to be ready. However, Security Minister Ben Wallace said there was no evidence of a specific threat over Britain's holiday weekend, when major events will take place including Saturday's soccer FA Cup final in London, where extra armed officers will be on duty.

As campaigning for a national election on June 8 resumed after it was suspended following the attack, the opposition Labour Party, emboldened by its rise in opinion polls, charged that Britain's foreign policy had increased the risk of attacks.

Labour leader Jeremy Corbyn also chided Conservative Prime Minister Theresa May for cutting spending on policing. "We must be brave enough to admit the 'war on terror' is not working," he said.

May hit back. "Jeremy Corbyn has said that terror attacks are our own fault," she said. "I want to make one thing very clear to Jeremy Corbyn and to you, and it is that there can never, ever be an excuse for terrorism."

She was speaking to reporters at a summit of Group of Seven leaders in Sicily where she won support for action to prevent militants from using the internet to spread propaganda.