Maldivian and Indian forces were on Tuesday shadowing a hijacked Iranian-owned cargo ship drifting in the Indian Ocean, but were holding off boarding the vessel, a defence spokesman in Male said.
The MV Eglantine was seized by Somali pirates late Monday off Hoarafushi island in the Maldives, the first hijacking in the waters of the archipelago.
"By the time our vessel reached the area the hijacked ship had drifted out of our Exclusive Economic Zone," a spokesman for the Maldivian National Defence Force, Abdul Raheem Latheef, told AFP by telephone from the capital Male.
"But we are tracking this vessel along with the Indian navy," he explained, adding that an armed Maldivian vessel was travelling close to the ship, seized over 2,000 kilometres (1,250 miles) from the pirate hotspot of Somalia.
The cargo carrier was loaded with Brazilian sugar destined for Iran and was heading to the Bandar Imam Khomeini port in Iran, Dow Jones Newswires reported, quoting the North Atlantic Treaty Organization's (Nato) shipping center.
The Bolivian-flagged Iranian-owned vessel had a total of 23 crew, but their nationalities were not immediately known.
The Maldivian authorities said they were alerted to the hijacking by the Global Maritime Distress and Safety System, the emergency communications system for global shipping, which maintains an operation in the Maldives.
In November, the Maldives announced it was working with Sri Lanka and India on a strategy to deal with Somali pirates. The Maldives had arrested 37 Somali pirates who were drifting near the archipelago.
Sri Lanka has also arrested an unspecified number of Somali pirates.
Two decades of lawlessness have carved up Somalia into mini-fiefdoms ruled by gunmen and militia, encouraging rampant piracy.
At least 40 vessels and more than 400 hostages were still being held in or just off Somalia at the end of last year, according to the Ecoterra International group which monitors piracy in the region.