Police stand outside a house in Colwyn Road, Beeston, England, on Thursday, following the arrest of 3 people on suspicion of committing, preparing or instigating acts of terrorism. ((Gareth Copley/Associated Press))

British police said Thursday they have arrested three suspects in connection with bombings in July 2005 on the London transit system that killed 52 commuters.

The attacks on July 7, 2005, were considered the deadliest on London since the Second World War. Until Thursday, no arrests had been made.

London Metropolitan Police said two men, aged 23 and 30, were picked up at the Manchester Airport in northwestern England as they were about to board a plane to Pakistan.

A few hours later, police picked up the third man, 26, at a house in the northern city of Leeds. Police were searching five houses in Leeds.

Police said they arrested the men on suspicion of committing, preparing or instigating acts of terrorism, and authorities said the three men would be questioned at a central London police station.

At the time of the arrests, police were searching five houses in Beeston, a working-class neighbourhood in Leeds in which three of the bombers had lived. Police said they were also searching an apartment and business in east London.

According to police, investigators were "determined to follow the evidence wherever it takes us to identify any other person who may have been involved, in any way, in the terrorist attacks."

The attacks on three subway trains and a bus in July 2005 also killed four suicide bombers.

Police identified the four asMohammad Sidique Khan, 30; Shehzad Tanweer, 22; and Germaine Lindsay, 19, who set off bombs onthe three subway trains;and Hasib Hussain, 18, who attackedthe bus.

With files from the Associated Press