Sania under threat again.

Indian tennis sensation Sania Mirza will receive extra security after an Islamic group opposed to her on-court dress threatened to stop her from playing in next week's WTA event, police said on Friday.

Muslim clergymen have denounced the 18-year-old player for wearing skimpy skirts and colourful sleeveless tops on court, which they say are un-Islamic.

The teenager has emerged as one of India's most visible sporting icons following a sensational year in which she has climbed to 34 in the WTA world rankings.

In a country dominated by cricket, companies are queuing up to sign endorsements with her.

Mirza has refused to be rawn on the controversy over her clothes and is scheduled to play in Kolkata beginning on Monday, despite the call by a powerful Islamic group to stop her.

The group, Jamaat-e-Ulema-e-Hind, has warned that.....ts members would try to prevent Mirza from playing if she did not wear "proper clothes."

"What she wears offends Islam. She will be stopped from playing if she doesn't adhere to it," Siddiqullah Chowdhry, the group's chief, told Reuters.

Police are tightening security following the call.

"We are keeping everything in mind and not taking any chances. We are making special and strong security arrangements," Gautam Chakraborty, additional police commissioner of Kolkata, told Reuters.

Scores of police officers are being deployed at the indoor venue for the tournament. Spectators will be frisked and will have to pass through metal detectors to enter the stadium.