(CNN) -- Activists working to break Israel's siege of Gaza remained afloat in the Mediterranean Sea after their ship was taken over Thursday in Libya, an official with their organization said.
The ship, the Strofades IV, was part of a Gaza-bound convoy sponsored by the independent activist group Road to Hope. The group said that the incident took place after the ship owner "went berserk" in an argument with an Egyptian broker.
Ten convoy members -- seven Britons, two Irish citizens and an Algerian -- were taken hostage, the group said. As many as seven Libyans, including customs inspects and border police, were also being held on the ship, according to Road to Hope.
"All of them are gelling together and staying as a team," Leyla-Rubaina Hyda, a British representative for the activist non-profit group, told CNN.
According to Hyda, who talked to a Road to Hope member on board the ship, the hostages "are all doing fine." In a release, fellow Road to Hope official Ellie Merton wrote that all 10 had used mobile phones to contact friends and family.
After first being confined to the loading bay in the back of the ship, the activists were moved to a smoking room where they have been given a meal, Merton said, based on her conversations with crew members.
Two Road to Hope members found a radio and sent a mayday message, Hyda said, and soon thereafter they saw military jets flying around the ship.
Road to Hope's Facebook page stated that four Libyan naval vessels and two fighter jets had surrounded the ship, before it headed into international waters. Still, there was no rescue on Thursday night, and Hyda said the ship later appeared to be approaching Crete.
The British Foreign Office said its diplomats, as well as others, were working to resolve the crisis.
"We are aware of the incident at Derna Port in Libya, and have been in close contact with the convoy organizers," the British Foreign Office said.
"Our embassy in Tripoli has been urging the Libyan authorities to resolve the situation rapidly and ensure that those caught on the ship are returned to safety.
"Our embassy in Athens has spoken to the shipping company and is also in close contact with the Greek authorities. Our priority remains that there be a safe resolution to this incident."
Greece's Foreign Ministry said Thursday that the ship -- sailing under a Maltese flag -- is heading toward the Greek island of Crete but was still in international waters. The ministry initially said the ship was Maltese-owned but later said the vessel may be partly Greek-owned.
"The matter is a serious breach of every maritime law possible. We have asked all relevant embassies to supply urgent, immediate, consular assistance. We are extremely concerned for the safety of all the nationals on board," Road to Hope said in a statement.
CNN's Eileen Hsieh and Joe Sterling, and journalist Elinda Labropoulou contributed to this report