THE PSNI are investigating a number of reports of a loud bang in Derry/Londonderry overnight.
It was heard in the Bogside at around midnight on Thursday.
The PSNI’s ‘Hawkeye’ helicopter went airborne in a bid to help officers on the ground locate a possible site for the explosion.
Despite extensive searches, nothing has been found and the source of the bang is still being investigated.
A police spokesperson said: “Police in Derry received a number of reports of a loud bang in the city at around midnight on Thursday 25 April.
“Extensive police checks were carried out in the area by officers on the ground and the police helicopter but nothing was found.
“Police would ask members of the public to be vigilant and if they see any suspicious items not to touch or attempt to move the item but call police immediately.”
Deputy First Minister Martin McGuinness also heard the bang and tweeted about the incident.
The Sinn Féin MLA tweeted: “Loud explosion in Derry few minutes ago, whatever caused it, hope there are no casualties.
“Helicopter in the sky, nothing reliable so far on location of explosion, though if there were casualties I’m sure we’d have heard by now.
“Police say they are unable to locate seat of explosion, relieved it appears so far no one hurt. Bedtime.”
Police in the city have recently thwarted two attacks by dissident republicans.
In one incident, a van was rammed on its way to Strand Road police station.
Inside the van police found primed rocket launchers and the roof had been cut back in preparation to launch the devices at the station.