LONDON (Reuters) - British police have arrested four men on suspicion on preparing acts of terrorism as part of investigations into Islamist-related militancy.
One was detained by armed officers on a London street, police said in a statement.
The men, aged 19, 22, 25 and 27, were arrested in west London and in Thames Valley, to the west of the capital, on Thursday night and Friday morning.
Armed officers were also present for two of the other arrests but no shots were fired.
The men are now being questioned at a police station in central London and several homes and vehicles were being searched. No further details were immediately available.
The arrests are the latest in a series to have been carried out by British counter-terrorism officers since the country's threat level was raised to its second-highest level in August due to the risks posed by Islamic State fighters returning from Iraq and Syria.