The national capital was today put on a high alert in the wake of a blast in Maharashtra's textile town of Malegaon.Security has been stepped up at all vital installations and places of worship while checking has been intensified at all entry and exit points. A tight vigil is also being maintained at crowded places including railway and bus stations, cinema halls and market places."We have alerted our personnel," City Police Commissioner K K Paul said. Police have also asked the public at large to inform the police immediately in case of finding any suspicious object.