Hanoi  - A tanker carrying diesel fuel and a ship carrying vegetable oil collided, spilling the oils just outside one of Vietnam's busiest ports, a local official said Friday.

The Vietnamese diesel tanker was leaving the port of Saigon and heading back out to sea when the accident happened on Wednesday night, said Dang Hoang Son, the Chief of the Secretariat of Thanh An commune in Ho Chi Minh City.

"We don't know how much diesel fuel spilled into the river at night, but we used a float to surround it and sucked it into another tanker," said Son. "It took about three hours to finish."

State-run media said that the tanker, identified as Gia Dinh-SG 4193, was carrying 700 tons of diesel fuel when it collided with the Imextrans 16, which was carrying vegetable oil.

Son said that a small amount of vegetable oil had also leaked into the Long Tau River but clean-up crews were working on sucking up the spill.

Accidents in the Mekong Delta, which ships use to transit to Ho Chi Minh City, are all too common. The rivers in the area, which are dumping grounds for industrial waste, are some of the most polluted waterways in the world.

According to the US Agency for International Development (USAID) some 10,000 vessels operate in the area each year. The large number of ships, navigational hazards and human error have resulted in relatively frequent oil spills, the agency said.

Only the day before the accident, the Association of South East Asian Nations Ports Association had wound up its annual conference in Ho Chi Minh City.

Ho Kim Lan, secretary general of the Vietnam Seaports Association, told reporters at the conference that Vietnam "lacks the material facilities and qualified people to develop the port system further."

Earlier this week, there was a small oil spill at the Dung Quat oil refinery in central Vietnam, which occurred as workers were conducting a test-run before the refinery officially opens next year. (dpa)