The police have registered a case of theft.

Unidentified thieves allegedly stole mobile phones and other valuables from the parked vehicles of marathon participants in south Mumbai early on Sunday, the police said.

The fourth edition of the Indian Oil Western Naval Command (WNC) marathon was held here this morning, in which thousands took part. The event was flagged off at Ballard Estate near the Naval Dockyard.

"Many of the participants had parked their cars on nearby roads before going for the marathon run. When they returned later, some of them found that the windows of their cars were smashed and their valuables stolen from inside," an official of Azad Maidan police station said.

"Most of the cars were parked in the area under the jurisdiction of Azad Maidan Police Station. Many participants complained that their mobiles phones, wallet, documents and other things were stolen," he added. Police have registered a case of theft.

"A probe has been launched. We are now going through the footage of the CCTV cameras installed there. It appears to be a handiwork of a gang and not a single person," the official said.