Photo: Gonzalo Fuentes/Reuters

Security staff numbers have been increased for Roland Garros, which starts on Sunday, officials announced in the wake of a suicide bombing at a pop concert in Manchester that left at least 22 dead.

"We've accredited 1,200 security staff, which is a little more than in 2016," said Jacques Le Mene, head of security at the French Open.

French tennis federation (FFT) spokesman Stephan Post added that France remained at level two of its security alert system, Plan Vigipirate, which specifies reinforced security and risk of attack.

"There's been no particular advice from our security partner, the Paris police," Post said.

"We really make security a priority in our actions. We're not experienced in a situation of an attack in the sense that we've not experienced one, but we're trained, we've done simulations and training drills.

"With the experience of last year, our system is more efficient."

As in 2016, the FFT has installed a three-ring layer of security, with around 450,000 spectators expected between Sunday and the men's final on June 11, with peaks of 35,000 fans for the busiest days.