Missing Vietnamese oil tanker found raided by pirates

(CNN) -- Almost one week after vanishing en route from Singapore to Vietnam, a Vietnamese oil tanker has been released by pirates who had taken control of the vessel.

Nguyen Nhat, director of Vietnam's Maritime Department, told CNN that the eight pirates who seized the ship absconded with part of the cargo -- 2,000 metric tons of a total 7,200 metric tons of oil.

The ship, called Sunrise 689, had returned to Vietnam with its 18 crew, arriving in port at 5 p.m. local time (6 a.m. ET). The nationality of the pirates was unknown, he said.

The ship's owners lost contact with the vessel just 40 minutes after it departed Singapore on October 2, according to the Vietnamese News Service (VNS), citing the ship's owner, the Hai Phong Seafood Shipbuilding Joint Stock Company. It had been due to arrive in Vietnam on October 5.

VNS reported that Vietnam's Foreign Ministry had sent "diplomatic notes" to the embassies of Singapore, Malaysia, Brunei and Indonesia in Hanoi, asking for assistance in finding the missing ship, which had disappeared from radar.

Piracy rising in Asia

Southeast Asia has become a prime target for pirates who have staged a number "serious attacks" on tankers in the region, according to the International Maritime Bureau (IMB).

According to a report released in July, there had been at least six known hijackings since April, when small coastal tankers were targeted for their cargo of diesel or gas oil.

"The recent increase in the number of successful hijackings is a cause for concern," IMB director Pottengal Mukundanm said at the time.

Until this year, most attacks had been petty thefts perpetrated on boats anchored at harbor, the IMB said.

Sunrise 689 dropped off radar in the middle of a busy shipping zone in the Singapore Strait.

According to warnings issued by the IMB, vessels in the Singapore Strait are advised to "remain vigilant and to continue maintaining adequate anti-piracy / robbery watch and measures. Pirates / robbers attack ships while underway or while at anchor especially during the night."