The two British hostages on board the hijacked Sirius Star were named by their families last night after another day of drama in the Gulf of Aden which included the Indian navy destroying a pirate "mother ship".

The two British hostages on board the hijacked Sirius Star were named by their families last night after another day of drama in the Gulf of Aden which included the Indian navy destroying a pirate "mother ship".

Peter French, a chief engineer from Co Durham, and his crew mate James Grady, a second officer from Strathclyde, are two of at least 25 hostages now known to be on board the Saudi-owned supertanker that was seized off the coast of Kenya at the weekend, carrying a $100m (£67m) cargo of oil.

In a statement released through the Foreign Office, the two crew members' families said they hoped to be reunited swiftly with their loved ones. "The families... greatly appreciate the concern that has been expressed by people throughout the UK and beyond, about Peter and James. They hope that Peter and James will be home safely with their families very soon."

Last night, the owners of the Sirius Star were said to be negotiating a possible ransom. The ship and its cargo – believed to be the biggest booty ever seized by pirates – is being held at the pirate stronghold of Harardhere in Somalia. The Saudi Foreign Minister, Prince Saud Al-Faisal, said his government opposed negotiations with pirates but that the ship's owners were the "final arbiter".

A Dubai-based spokesman for Vela International declined to comment on the ransom specifically. "We hope there will be a quick solution," he said.

Mark Dolan, a friend of Mr French and a former sea captain who regularly sailed through the pirate-ridden waters surrounding Somalia and Yemen, said his friend would be annoyed about being captured. "I think he will be most angry and frustrated and itching to have a go back so hopefully he will bide his time and not do anything silly," he told the BBC.

He also described how little protection commercial shipping had from pirates in the area. "We have trained lookouts and, at night, we have extra light we can use but apart from that the only other defence we have are high pressure fire hoses," he said. "By then it's too late."

The naming of the British hostages came just hours after the Indian navy announced it had destroyed and sunk a "mother ship" belonging to pirates operating off Somalia. Another smaller vessel escaped and was later found abandoned.

The Indian frigate INS Tabar, one of dozens of warships from a number of countries that have been dispatched to the Gulf of Aden to protect shipping, attacked the Somali pirate ship on Tuesday evening after reportedly coming under fire.

In Delhi, navy spokesman Nirad Sinha said the sinking of the vessel happened when the Indian warship tried to carry out checks. "The INS Tabar closed in on the mother vessel and asked her to stop for investigation. But, on repeated calls, the vessel's threatening response was that she would blow up the naval warship if it approached," he said. The spokesman said an exchange of fire then took place, resulting in explosions on the pirate vessel, which subsequently sank.

However, on the same day that the Indian navy struck back at the pirates, three more vessels were captured – a Thai ship with 16 crew members, a Greek vessel and an Iranian cargo vessel with a crew of 25.

There has been a surge in pirate activity off the coast of Somalia, something experts say is the result of general lawlessness and a growing Islamic insurgency in a country that has been without a proper government since 1991. Since the beginning of the year, 39 ships have been hijacked in the Gulf of Aden, out of a total 95 attacked.

"It's getting out of control," said Noel Choong of the International Maritime Bureau's piracy reporting centre in Malaysia. "There is no firm deterrent, that's why attacks are continuing."