A suspected World War Two bomb found at a housing estate in Newtownards in County Down is to be “dealt with on site”, police have said.

Police said the decision followed discussions at great length about whether the 500kg (1,100lb) device should be removed or dealt with at the scene.

The device was assessed and a decision was made not to remove it.

Military experts have worked to reduce any damage from dealing with the bomb, including by constructing of a sand-filled structure around it.

However, the Police Service of Northern Ireland (PSNI) has warned that there was “a risk of death or serious injury to anyone who does not leave the area”.

More than 400 households were told to evacuate the Rivenwood housing development in Newtownards by 10:00 BST on Sunday.

On Saturday evening police said that the operation to neutralise the bomb, which has now entered its third day, could take “five or more days to complete”.

“If officers have engaged with you to evacuate, your cooperation at this time would be greatly appreciated to assist with the ongoing efforts to complete the operation and make the area safe again,” a PSNI statement said on Tuesday.

The police have not yet confirmed what type of explosive has been found, describing it as a “suspected historic piece of munition”, but Belfast and its surroundings were heavily bombed by Germany in 1941.

World War Two munitions are found across Northern Ireland from time to time, but they rarely cause this level of disruption to people living nearby.