Mumbai, Aug 7 (IANS): A cargo vessel which sunk off the Mumbai harbour Thursday has been leaking oil, an official said Sunday.

"Oil has been observed leaking from the sunken vessel Rak Carrier since late Saturday at an approximate rate of 1.5-2 tonnes per hour," a navy official said.

"Coast Guard ship Samudra Prahari on patrol immediately responded and used oil spill dispersant to neutralise the spilled oil. Operation 'Paryavaran Suraksha' has also been launched by the Coast Guard," he added.

According to the official, an aerial recce conducted Sunday morning indicated spread of oil up to seven nautical miles from the sunken vessel.

The Coast Guard has pressed another vessel, ICGS Sankalp, in the area, he added.

However, the coastal authorities have been advised to maintain strict vigil. "State authorities have also been advised to direct fishermen to refrain from fishing in the vicinity of the affected area," the official said.

The ship MT Rak Carrier, laden with 60,000 tonnes of coal and 340 tonnes of fuel and diesel, sank Thursday afternoon, raising apprehensions of an ecological hazard.

The 30 crewmen aboard -- all Indonesians, Jordanians and Romanians -- were rescued in a coordinated effort by the Indian Navy and Indian Coast Guard.

The Panama-flagged ship, owned and managed by M/s. Delta Shipping Marine Services, Qatar, was on a voyage from Lubuk-Tutung, Indonesia to Dahej Port in Gujarat, carrying a consignment of coal meant for Adani Enterprises Ltd.

Two top officials of the cargo vessel were Saturday arrested and later released on bail by a Mumbai court.

The duo -- Jordanian Capt. Arkan Younis, 36, and Romanian chief engineer Eonascho Eon, 54 -- were nabbed under the Indian Penal Code (IPC) Section 336, pertaining to endangering life or personal safety of others.