Somali pirates have demanded a ransom for the Saudi super-tanker Sirius Star.
A man presented as one of the pirates said on a recording on Al Jazeera TV today that negotiators were on board the tanker and on land in an unidentified location.
He did not say how much was being demanded.
Somali pirates have hijacked three other ships since capturing the Sirius Star on Saturday in one of the worst spates of attacks in Somalia's waters.
Andrew Mwangura from the East African Seafarers' Association said a Thai fishing boat, a Hong Kong-registered cargo and a Greek bulk carrier had been seized yesterday in the Gulf of Aden.
An Indian warship deployed in the gulf fought off pirates last night and destroyed their vessel after a brief battle.
Two accompanying speed boats sped away after the main vessel was blown up.
