Prayers have been said across the UK for the victims of the London bombings, with leaders from all faiths condemning the terrorists in special Sunday services.
It comes amid warnings from police that the bombers who killed at least 49 people could still be at large.
Authorities now believe at least three of the four bombs were detonated by timers.
Forensic teams are trying to piece together what happened but progress is slow as they describe conditions near King’s Cross underground station as like “hell on earth.”
DCC Andy Trotter of British Transport Police said: “They are continuing to work through the train looking for any other bodies that may be trapped underneath.
“Because of the difficult working conditions down there, this is a slow, painstaking and methodical task.
“They are working their way towards the back of the train to search for more bodies and forensic material.”
So far, police have not made any arrests directly linked to the attack, which the government says bears all the hallmarks of a group with ties to al Qaeda.
A former Metropolitan Police chief says he thinks the bombers were “almost certainly” British.
As the site of the bus blast is cleared, three men have been detained at Heathrow Airport under Britain’s anti-terrorism legislation.
Scotland Yard has warned against jumping to conclusions, saying any link would be “pure speculation.”