VILLENEUVE D'ASCQ, France (AFP) - Cuban athletes Dayron Robles and Yargelis Savigne gave warnings to their Olympic rivals here on Friday while top French sprinter Christine Arron disappointed on her return.

Robles confirmed his scintillating form to clock 12.96sec in the 110m hurdles, just 0.09sec outside his own world record despite cold conditions and an unfavourable wind. It was also the ninth fastest time ever.

The 21-year-old Robles had run 12.87 in Ostrava, Czech Republic, on June 12 to beat the previous world record of 12.88sec set by China's Liu Xiang on July 11, 2006 in Lausanne, Switzerland.

"At first this competition was about finetuning technical aspects," Robles said afterwards. "But I was really in good form and, looking at the conditions, I am very surprised by this time which is my third best ever."

Robles's compatriot Savigne, the outdoor and indoor world triple jump champion, earned the best performance in the world this year of 15.02m to easily beat Ukraine's Olha Saladuha (14.52m) and reigning Olympic champion Francoise Mbango of Cameroon (14.36m).

Arron, a world bronze medallist in both 100m and 200m last year, returned to action this season with a disappointing 11.47sec over the shorter distance.

With the start of the Olympics barely a month away, Arron admitted she had work to do but was optimistic of being up to scratch by the time the athletics events start on August 15.

"I don't want to start worrying because I have to get to work," said Arron, who postponed her return to the track, scheduled a month ago, four times because of back and groin problems.

"I will really start to worry if I have not progressed by mid-July but for the moment I need to get some training sessions under my belt to improve my speed."

Her next scheduled outings are in Reims, France, on July 8, in Tangiers, Morocco on July 13, then in Paris five days later.