Timeline: UK sailor crisis

March 23: 15 sailors and marines arrested by Iran after searching a merchant vessel in the Gulf. Iran claims that the 14 men and one woman were illegally in Iranian waters

March 24: Iran says that the sailors were arrested because their entry into Iranian waters was suspicious

March 25: EU demands that the 15 Royal Navy personnel are released while British Prime Minister Tony Blair describes the incident as ‘very serious, maintaining that the boat was not in Iranian waters

March 26: Iran says it is considering charging the sailors with illegally entering their waters

March 27: Tony Blair warns Iran of the conflict reaching a ‘different phase' if the sailors are not released. Oil prices climb due to the uncertainty caused by the crisis

March 28: Britain says that GPS satellite data proves that the sailors were 1.7 naughtical miles inside Iraqi waters when they were arrested

March 29: Britain freezes contact with Iran, but Iranian officials later say that Britain needs to apologise before the sailors can be freed and postpone the release of Faye Turney, the only female among the group

March 30: One of the captured men Nathan Thomas Summers is shown on Iranian TV confessing to being in Iranian waters

April 1: Iran says that legal proceedings have begun against the 15 but denies that a trial had started. Small explosions are heard at the British Embassy in Tehran during a protest but no-one is hurt.

April 2: US President George W Bush says Iran's behaviour is ‘inexcusable', Iran accuses US jets of violating its airspace. More footage of the captured sailors is aired on Iranian TV

April 3: A conciliatory tone is adopted by both sides as Iran says it does not think the matter needs to go to trial.

April 4: The 15 sailors and marines are told they can go free at a press conference in Tehran.