QINGDAO -- Postponing a popular beer festival, recruiting underwater robots and deploying navy ships -- these are just a few measures Olympic co-host city Qingdao is using to fend off any possible terror attack.

The renowned coastal resort in east China's Shandong Province has launched a security network that covers a sea area of 50 square km where the 29th Olympic Games' sailing competitions will be held, said the city's  mayor Xia Geng.

"In terms of the security and safety during the Olympics in Qingdao, anti-terror work is top priority for us," said Xia, also the Qingdao Olympic Sailing Committee chairperson.

One of six co-host cities for the Olympiad, Qingdao will host sailing events that run from August 9 to 23. Some 400 athletes from 65countries and regions will compete for 11 gold medals.

Qingdao police have placed the competition area under close monitoring by using underwater robots with video cameras, as well as bomb-detecting devices and helicopters, according to Zhao Chunguang, Qingdao Public Security Bureau director.

He said the security measures had been successfully tested during two trial events for the Olympic sailing competition in 2006 and 2007.

The Chinese navy will also deploy ships around the cordoned area, and a group of frogmen from the navy will conduct underwater security checks ahead of the competitions.

In order to fully focus on the Olympic security work, the Qingdao government has decided to postpone its annual international beer festival until September 19 to October 5.

The 17-year-old festival that usually takes place in August has become a big attraction where local and foreign tourists alike enjoy copious amounts of beer, particularly the city's best-known brew Tsingtao Beer.

Xia Geng said the massive algae bloom that threatened the Olympic sailing venue last month had been cleared, which enabled all the teams to carry out their pre-Olympic training.

Starting in mid-June, the sea-blanketing algae bloom from the Yellow Sea coated Qingdao, covering 32 percent of the sailing venue at the peak of the outbreak. More than 1,400 boats and 10,000 troops and volunteers were dispatched to clear more than 1 million tons of algae.

Two barriers have been installed since then to keep algae from the sailing venues. Ships, helicopters and satellite technology will also be used to monitor the area.

"With all these measures, we will be able to prevent the algae bloom from disrupting sailing events during the Olympics and the following Paralympics," Xia said.