Thousands of soldiers and volunteers in east China's coastal city of Qingdao, host of the Olympic sailing events, are still battling a major algae bloom on Friday.

More than 1,200 vessels were at sea cleaning the foul-smelling algae, and inflatable barriers were placed near the coastline to prevent the algae from encroaching on the shore.

According to an emergency headquarters set up to clean the algae, its coverage in the sailing competition areas, which span more than 50 square kilometers, had shrunk from 32 percent five days ago to less than 10 percent.

More than 110,000 soldiers and volunteers have been engaged in frantic efforts to cleaning the weeds, which was first spotted at the end of May and started to bloom in mid-June.

A municipal government figure published on Wednesday showed the algae had been nearly halved since late June and covered 48.8 square kilometers of water by Wednesday.

On Friday, sporadic remains of algae floated on the water off the Olympic sailing base. Dozens of boats were at sea gathering the algae. An aerial survey was delayed as rain and fog grounded helicopters.

At beaches near the base, soldiers were bagging piles of green algae which were dragged out of the water.

"It's far better now than a few days before, and the water is clearer. Last week, the air was rancid because of the algae, and we all shut our windows," said Zhang Xiaolei, whose office is near the coast at the May 4th Square.

By Thursday, about 285,000 tons of the algae have been removed from the water and seashore. Officials planned to wipe out the algae, called enteromorpha prolifera, before July 15.

Experts from the State Oceanic Administration (SOA) are working to determine the source and cause of the algae outbreak.

The algae also covered parts of a training area, where sailors from more than 30 countries are training, and sometimes blocked sailing routes and affected preparations for the sailing teams for the Games.

The sailing competitions are scheduled from August 9 to 23.

(Xinhua News Agency July 5, 2008)