Police Commissioner received the email yesterday after which investigation into the matter was initiated by city police and Anti Terrorist Squad, a senior Rajasthan police office told PTI.
"Primary investigation suggests that it could be a prank. The accused would be traced soon," he said.
Two suspicious men carrying tiffins on their cycles near Chandpole Hanuman temple were spotted on Tuesday, following which the police thoroughly checked the walled city area. The duo was not traced.
The police yesterday released a sketch of a suspect and appealed to people to co-operate with them to identify him.