Police have carried out a controlled explosion after two vans were hijacked by masked men in separate incidents in Northern Ireland, less than 48 hours after a suspected New IRA terrorist attack.

Officers said four masked men stole a white transit van and threw something into the back of it on Circular Road at about 11.30am on Monday.

A cordon was put in place and homes were evacuated before the explosion was carried out by specialist crews.

In a separate incident, a delivery van was intercepted by four masked men at around 1.45pm on Monday – one who reportedly had a gun  – and ordered the two occupants to drive to Lonemoor Road and leave the vehicle there.

Superintendent Gordon McCalmont said: “We are in the process of implementing a public safety operation, establishing cordons and evacuating a number of homes. 

“Sadly, within two hours today, we are dealing with a second security alert in the City, which means even more disruption for the local community.”

On Saturday a car bomb exploded on Bishop Street, but police were able to evacuate the area beforehand and no-one was injured.

Five people have been arrested, ranging from the ages of 21 to 50, in relation to the incident and the police said the New IRA is their primary line of inquiry.