Over 50 schools here received bomb threats via email on Monday morning, triggering panic among students and their parents, police said.

However, no explosive or anything suspicious has been found so far in these schools, they added.

The threatening emails to schools came 12 days after a similar scare in Delhi-NCR where 150 schools received bomb threat emails from a Russia-based mailing service on May 1, triggering massive evacuations and searches. On Sunday, 20 hospitals, including the IGI Airport and the Northern Railways' CPRO office, in Delhi received similar emails. The authorities declared both the incidents as hoax.

The emails to schools in Jaipur also happen to come on the 16th anniversary of the serial bomb blast incident in the Rajasthan capital. A series of blasts had rocked the city on this day in 2008 claiming 71 lives and injuring 180 people.

According to the police, 56 schools in Jaipur received emails stating explosives were planted on their premises. On being informed, squads were rushed to these locations to check for suspicious objects or devices.

No suspicious objects were found wherever the checks have been completed, the police said.

"The locations have been sanitised and marked clear from the security point of view," a police officer said.

The first information about the threat was reported from a private school in Tilak Nagar followed by other schools in different localities including Manak chowk, Vaishali Nagar, Vidhyadhar Nagar, Niwaru Road, Tonk Road, and Sanganer among others.

Soon after the threatening messages came to notice, students and staff members were evacuated from the schools.

Police teams and bomb and dog squads were rushed to these schools, Police Commissioner Biju George Joseph said.

"Several schools received threats via email that explosives were there in the schools. Checking in most of the schools has been completed and no explosive was found," he said.

Joseph said efforts are on to identify the sender of the emails, adding that all the messages were generated from a single source.

The police commissioner said the strictest action would be taken against those involved in the matter.

As soon as the news of the bomb threats spread, parents rushed to the schools in panic to pick up their children. However, they took a sigh of relief when authorities told them things were under control and there was no need to worry.