Mumbai Police has claimed a major headway in the serial bomb blasts probe with the preparation of over half a dozen sketches of suspects involved in Tuesday's blasts, sources said.

"The sketches have been prepared after getting details from an eyewitness and scores of persons injured in the blast," a senior crime branch official told PTI in Mumbai on Wednesday.

The sketches will be distributed among all crime branch units and special teams of the Anti Terrorism Squad formed to probe the blasts, sources said, adding that the sketches are unlikely to be released to public to maintain confidentiality of the probe.

Meanwhile, Police Commissioner A N Roy held a meeting of Crime Branch officials late Wednesday night and sought their help in the probe. Joined by senior police officials, including Joint Police Commissioners Arup Patnaik (Law & Order) and Meera Borwankar (Crime), the police chief asked crime branch officials to contribute by providing clues in the case.

"Besides the ATS, the crime branch is also likely to undertake an independent probe into the blasts using its in-house expertise in tackling the underworld," a Crime Branch official said.