LONDON (AFP) - China's dominance of international gymnastics continued when they won three individual gold medals and a silver at the World Championships at London's O2 Arena.

Olympic champion He Kexin won the women's uneven bars while Zhang Hongtao, on the pommel horse, and Yan Mingyong, on the rings, were crowned champions in the men's competition.

To add to a sensational day for China, Olympic champion Zou Kai claimed silver in the floor exercise, which was won by experienced Romanian Marian Dragulescu.

The Chinese grabbed 12 individual medals at last year's Olympics in Beijing and their team proved too strong on the third day's action at an arena that will host gymnastics at the 2012 Games.

The 17-year-old He, who outclassed a high-quality field in the bars, insisted she and her team-mates have not been feeling the pressure to maintain the country's success in the sport following Beijing.

"We have been feeling relaxed," she said, through a translator.

"There is no pressure. There are no team events here so we could focus solely on our own events.

"We have just finished our national championships so physically we are not at out best, so we are just trying our hardest."

Yan added: "Our coaches have just told us we need to relax. We have kept on practising like we always have."

In the fourth of Saturday's five finals, He cruised gracefully through a tough routine before nailing her landing and scoring 16.000 points.

She beat the silver medalist, Japanese sensation Koko Tsurumi, by more than a point. Romania's Ana Porgras and Rebecca Bross of the United States shared bronze by both scoring 14.675.

Bridget Sloan, the American who won all-round gold here on Friday, could only come sixth.

Minutes earlier, He had seen compatriot Zhang produce a stellar performance on the pommel horse.

Showing amazing hand speed, Zhang - who did not compete in Beijing last year but qualified in first position here - scored a superb 16.200 to see off 2007 world silver medalist Krisztian Berki, from Hungary.

Australia's Prashanth Sellathurai took the bronze, to add to his silver medal in the same discipline at the 2006 worlds. Related article: Prashanth Sellathurai

"I did very well - it was almost perfect," said Zhang.

Local favourite and Olympic bronze medallist, Great Britain's Louis Smith, finished eighth after stumbling off the horse early on in his routine.

The field in the men's rings was wide open following the failure of China's Olympic champion and two-time world champion Chen Yibin to qualify.

Team-mate Yan took full advantage, wowing the crowd with stunning control to pip Bulgaria's Iovtchev -- the two-time world champion -- to gold even though the Chinese star stumbled forward on landing.

"The landing was not a big mistake. I made just one step forward," Yan said. "I still thought I was going to win (despite that)."

Ukraine's Oleksandr Vorobiov took bronze.

Dragulescu denied China a fourth gold as the Romanian beat Zou to the floor title.

Zou opened the final with an excellent routine but 28-year-old Dragulescu, who has just come out of retirement after recovering from back and neck problems, overhauled him by 0.025 pts.

He won floor gold in the 2001, 2002 and 2006 world championships, while he is also a three-time world champion on the vault.

"After my (retirement) break, I was feeling good and I said to myself I should come back and give it another shot. I am glad I did," said Dragulescu.

Zou, a national hero in China after his three individual titles in Beijing last year, grabbed silver and Israel's Alexander Shatilov picked up the bronze.

In the other individual final on Saturday, 16-year-old Kayla Williams of the US picked up gold in the women's vault.

North Korea's Olympic champion Hong Un-Jong fell on landing in both her attempts, costing herself any chance of a medal.

Williams, who was first in qualifying, took full advantage by nailing both her landings and maintaining great height and form in her vaults to sweep to gold with a score of 15.087 pts.

European champion Ariella Kaeslin of Switzerland earned silver with France's Youna Dufournet taking bronze.

Hong, despite her foibles, came fourth, mainly due to the difficulty of her attempts.