Greek police say a man has admitted killing a 17-year-old Briton who died after a fight on the resort island of Rhodes.
Some of the arrested Britons are led to court
Irish-born Paddy Doran, from Peterborough, Cambridgeshire, was stabbed in the neck with a broken bottle.
Ten Britons arrested after the death of the teenager in Faliraki on Tuesday have appeared before a public prosecutor.
One man has been charged with manslaughter, according to police chief Ilias Halivopoulos.
The Foreign Office said 18 British nationals had been arrested and faced a range of charges which in some cases included drugs offences.
It is known that five of the men are from Liverpool and three are from Northern Ireland.
Police chief Ilias Halivopoulos said: "One of
the men confessed during the preliminary investigation that he struck the other man with the bottle."
A Foreign Office spokesman said: "Consular staff met with them before a formal arrest had been made and offered consular assistance and details of English-speaking legal representatives."
Greek police said the victim became involved in a brawl with 10 other Britons
in a club called Q in the early hours of Tuesday.
The Foreign Office said on Wednesday that the victim's next of kin had been informed, but refused to confirm his name as he was a minor.