High alert has been sounded in Naxal-infested districts of Maharashtra in the wake of a deadly attack by Naxals in Dantewada district of Chhattisgarh in which they blew up a bus killing 31 people, police said today.

"The security forces have been asked to be alert and advised to follow Standard Operating Procedure (SOP). Naxal- hit districts of Gadhchiroli, Gondia and Chandrapur have been put on high alert," PRO of Gadhchiroli police N Jagtap told PTI.

All precautionary measures have been taken to avoid any untoward incident, he said adding that private vehicles and public transport were being checked and suspicious people were being frisked.

The personnel of Central Reserve Police Force (CRPF), State Reserve Police Force (SRPF) and district police deployed at Naxal affected areas have been adviced to strictly follow SOP and not to move in large groups and avoid using civilian vehicles.

Meanwhile, Director General of Police A N Roy and other top police officials have inquired about situation in Naxal infested districts in the state in the wake of yesterday's naxal attack in Chhatisgarh, in which civilians and special police officers were killed, the sources said.

There were also intelligence inputs received a few weeks ago that Naxals might strike in Gadhchiroli district, they said.