British police have arrested a 14-year-old boy in connection with an alleged plot to attack a war memorial ceremony in Australia.

Greater Manchester Police says the boy was detained in Blackburn, northwestern England, on Saturday on suspicion of involvement in the commission, preparation, or instigation of acts of terrorism.

Detective Chief Superintendent Tony Mole said Monday the arrest came after police found "communication between an individual in the northwest and a man in Australia to what we believe is a credible terrorist threat."

He said police had not uncovered an imminent threat to Britain.

The force said it had passed information to Australian authorities.

On Saturday police arrested five Australian teenagers on suspicion of plotting an Islamic State group-inspired attack at an ANZAC Day ceremony in Melbourne later this month.