London: Seven British aid workers are among a group being held in the Libyan sea on board a boat due to deliver aid to Gaza, a Foreign Office spokesman confirmed.
"We are aware of the incident at Derna Port in Libya and we have been in close contact with the organisers," the spokesman said.
"We understand that the ship is now heading towards Greek territorial waters," they added.
The spokesman could not confirm reports that the Strofades IV ship was surrounded by Libyan navy ships and fighter jets.
Ellie Merton, London liaison for the organisers, Road to Hope, said she thought the group were being held by the ship`s Greek captain after a dispute over money.
"As far as I know, the boat owner became really aggressive over a payment for something, tried to shut the back end of the boat and moved away from the pier really fast.
"We`re extremely concerned -- the boat`s not seaworthy and the captain has shown he is willing to risk life and limb of himself, his crew and the aid workers."
Merton said there were also two Irish, an Algerian and three Libyans on board, as-well as two policemen and a port manager who were not part of the convoy.
One of the Britons on board is Tauqir Sharif, who was aboard the Mavi Marmara ship which was raided by commandos from the Israeli Defence Forces while en-route to Gaza in May, resulting in the deaths of nine activists.