UNDER ATTACK: July 7th - Four blasts rip through London during the morning rush hour, killing at least 56 people including the four bombers. Seven hundred people are wounded.
Bombs explode on three packed underground trains and another blast later strikes a double-decker bus.
A previously unknown "Secret Group of al-Qaeda's Jihad in Europe" claims responsibility in the name of al-Qaeda shortly after the blasts.
July 12th - Police suspect four men of carrying out the bombings. They are later revealed to be British nationals.
Police search six houses in and around the northern city of Leeds, including the homes of three of the four suspects.
Some 500 people are evacuated in the search and police arrest a relative of one suspect and seize large quantities of explosives.
Police seize a vehicle in a car park in Luton, finding some explosives.
July 13th -- Security experts say the four would have received training and direction from a more senior militant.
July 14th -- Thousands of Londoners hold a vigil in Trafalgar Square at the heart of the capital.
July 15th -- Police find highly volatile home-made explosive at sites linked to four suspected attackers, security sources say.
London police chief Ian Blair says detectives are confident of finding an al-Qaeda link and warns that another attack is a strong possibility.
July 16th -- Prime minister Tony Blair says the "evil ideology" of al-Qaeda must be pulled up by the roots.
July 17th -- Police release CCTV pictures of the four walking into a railway station at Luton.
July 18th -- A report from the Royal Institute of International Affairs says backing the US in Iraq put Britain more at risk from terrorist attacks. The accusation is forcefully rejected by Mr Blair's government.
July 19th -- British Muslim leaders and Mr Blair discuss ways to tackle radical Islamists.
Chancellor of the exchequer Gordon Brown pledges an extra £20 million to fight terrorism and provide support for the bombing victims.
July 21st - Four small co-ordinated explosions strike three London underground stations - Oval, Warren Street and Shepherd's Bush -- and a bus in Hackney. One person is injured.
Mr Blair says the attacks are done to scare people.
Officials say that while the attacks have echoes of the ones two weeks ago,it is too early to tell if they bore the hallmarks of al-Qaeda.