Kolkata, March 18 (IANS): The naked body of a septuagenarian woman was found in West Bengal's Burdwan district on Wednesday, police said, as locals alleged she was raped before being murdered.

The discovery of the body in Katwa came on a day when Chief Minister Mamata Banerjee announced a CBI probe into the gang rape of a septuagenarian nun in Ranaghat in Nadia district.

"We have found the body of a 75-year-old lady who was an inmate of an ashram in Katwa. We have sent it for post-mortem examination to ascertain the cause of death as well as if she was raped. Prima facie it appears to be a murder case," a police officer said.

Perceiving that the woman was raped before being murdered, locals attacked the ashram.

Police subsequently intervened and detained a few of the attackers.

Leader of Opposition and CPI-M politburo member Surjya Kanta Mishra questioned Banerjee's silence over the Katwa incident.

"75 year plus old lady raped & murdered at Katwa. Will d CM tweet? Is it not sensitive & serious," tweeted Mishra, referring to Banerjee who had taken to Twitter to condemn the March 14 gang rape of the nun in Ranaghat.