A man, who allegedly engaged in vulgar act before an American woman in Mumbai, was on Tuesday booked by the Mumbai police on charges of outraging her modesty.

"We have registered a first information report under section 509 (word, gesture or act intended to insult modesty of a woman) of the Indian Penal Code and recorded the statement of the complainant," said Vinay Gadgil, senior inspector of Colaba police station.

"We are searching the accused through the photograph, which the complainant has given to us," he added.

On Monday morning, when the woman was walking in Colaba area of South Mumbai a man allegedly indulged in vulgar act in front of her, following which police launched a hunt for the accused.

The incident came to public notice when the American national tweeted about it, and her tweet soon went viral on social networking sites such as Tweeter and Facebook.

The victim also mentioned about two men, who where passing-by and came to her help when she raised an alarm. Meanwhile, an official told PTI that the woman, through a direct message on Twitter, was informed about the telephone number of Joint CP so that she could register the complaint.

"She replied Thank You, the police have been in touch and I am grateful to you," the official said.