Calcutta, July 28: The government has issued a red alert in West Midnapore, Bankura and Purulia in view of Maoist posters threatening to avenge recent deaths of comrades.

“We will observe Martyrs’ Day from July 28 to August 7; we will not only observe the death anniversary of CPI(ML) founder Charu Majumdar, but also teach a lesson to those who killed our comrades in the recent past - CPI (Maoist),” the posters read.

Intelligence sources said they were first seen on July 6, at Sambalpur in Orissa. After killing five people, said to be police informers, the rebels stuck the posters. Three police stations ? Belpahari in West Midnapore, Barikul in Bankura and Bandwan in Purulia ? have been identified as most sensitive.