Security agencies have been put on alert following a threat letter from terrorist outfit Al Qaeda [Images] to Mahant Nritya Gopaldas, a Ram temple movement functionary in Ayodhya.

The letter with a postal stamp of Haridwar in Uttarakhand was received by the mahant in Ayodhya on Thursday morning.

'Accept Islam along with your disciples or face death,' the letter reportedly said. Security for the mahant has been strengthened following this and an investigation has been launched, the police said.