London, May 27 (IANS): The number of people in custody in connection with this week's deadly suicide attack in Manchester increased to nine with the arrest of a 44-year-old man, police said.

The latest arrest took place in the Rusholme ward of Manchester on Friday and followed by a few hours the detention of another suspect in the inner-city Moss Side neighbourhood, Efe news reported.

Both arrests were part of a massive security operation launched after 22 persons died and dozens more were wounded Monday night in a suicide bombing during a concert by American pop singer Ariana Grande.

Authorities have detained a total of 11 people since the attack, but a 16-year-male and an adult woman were released without charges.

The nine people who remain in custody are men ranging in age from 18 to 44, including a brother of suicide bomber Salman Abedi, the British-born son of Libyan immigrants.

The bomber's father, Ramadan Abedi, and another sibling are now in the hands of authorities in Libya.

Ramadan Abedi is suspected of having been part of the Libyan Islamic Fighting Group, a faction supported by al-Qaeda, though he denies the allegation.

Though authorities have made "enormous progress" in the investigation, further arrests are likely, the head of the Greater Manchester Police Ian Hopkins said.

Police have "got hold of a large part" of the terror network behind the Manchester bombing, an official said earlier on Friday.