Malaysia's navy has fought off a pirate attack on a tanker off its east coast in the South China Sea, the International Maritime Bureau said Sunday.

The Malaysian force was assisted by the Indonesian and Singaporean navies in fending off the attack late Saturday, said Noel Choong, head of the IMB's Kuala Lumpur-based Piracy Reporting Centre.

The pirates fled the Singapore-managed tanker after navy patrol boats arrived before they could loot the vessel, the international body said.

"The Malaysian navy quickly dispatched a patrol boat and managed to intercept the tanker. Pirates managed to escape before the arrival of the naval boat," the IMB said in a report.

It added that the crew and cargo were safe, but gave no further details about the tanker or the pirates.

There has been a spate of pirate attacks recently in waters off Indonesia, Singapore and Malaysia.

The United Nations warned Thursday that Southeast Asia has become the world's piracy hotspot, after an international clampdown slashed the number of hijackings off the coast of war-torn Somalia.

Attacks in Southeast Asia topped 150 last year after starting an upward trend since 2010, the UN Institute for Training and Research (UNITAR) said in a report.

Piracy reports in the region had steadily dropped in previous years following stepped-up patrols and cooperation between neighbouring countries to secure waterways.