A Coimbatore-based organisation, Base Movement, has sent threat letters to prisons across the State saying that in the coming days it would avenge the assault on prisoners in Puzhal Prison and that the prison staff should count their days, said Coimbatore City Police sources.
Case registered
The Race Course Police here have registered a case based on a complaint from the Coimbatore Central Prison Superintendent D. Palani.
The sources said the movement, which said it was headquartered in Kottaimedu in the city, claimed it was linked to the Al-Qaeda and the threat letter was to take up the cause of prisoners who were in distress.
The group had sent a similar threat using social networking sites a couple of months ago.
The sources said the City Police alerted the prison establishments in other parts of the State and increased vigil in the city.
They were also conducting surprise vehicle checks.
