Police have launched an investigation after a "blast-like" sound was heard near a checkpoint on a vital bridge here, officials said on Wednesday.
The sound was heard late Tuesday night near a bridge over the Tawi river, the officials said.
There was no report of any casualty or damage in the "blast", they said.
Jammu Senior Superintendent of Police Chandan Kohli said "a blast-like sound was heard near Sidhra bridge checking point. A thorough search is being carried on the spot to verify the matter".
Officials said police reinforcements including Special Operations Group (SOG) personnel have rushed to the area.
A thorough search operation was carried out but no one was arrested during the night-long operation, they said.
Since the bypass is connected with the Jammu-Srinagar National Highway, an alert was also sounded and checking of vehicles was intensified.
The officials said forensic teams are visiting the spot to carry forward the probe.