London - British police on Saturday released two men arrested during a dramatic counter-terrorism operation in London last weekend.
London's Metropolitan Police said two other men remained in custody following a string of raids on October 13, in which armed officers shot the tyres of a car near the Tower of London.
A 29-year-old and a 28-year-old, who are Britons of Pakistani and Azerbaijani origin respectively, have been released without charge, the force said.
The two other British men, one of whom is of Turkish origin and the other of Algerian descent, were arrested after police shot at their car with Hatton rounds - special shotgun ammunition used to breach doors and tyres - 200 metres from the Tower of London, one of the British capital's busiest tourist attractions.
The two remaining suspects continued to be held at a south London police station on suspicion of the commission, preparation or instigation of acts of terrorism.
Police have until Sunday night to question them, after which they can apply for another seven-day extension.
The BBC quoted unnamed officials as saying the suspects were accused of a "serious" jihadist plot involving the use of firearms.