There has been serious flooding in Londonderry following heavy thunderstorms.
The storms started at about 1500 BST
The rain flooded houses, tore manhole covers off and left motorists trapped in their cars.
The water in some areas of the city was a foot high.
Duncastle Road, Strand Road and the Shantallow area were all affected.
In Victoria Road and Foyle Road, cars were trapped by the rising water.
The police said at least one car crashed into an open manhole.
At one stage, a search and rescue team which operates on the River Foyle was
also deployed in the city centre.
Inspector Bob Torrens, who said the storms started at about 1500 BST, advised people to remain indoors until the waters subsided.
"There were severe thunderstorms and very quickly because of the heavy rain some of the roads in the city started to flood," he said.
"There are eight so far and we are getting new reports all the time.
"This is causing virtual gridlock in the city. Nobody is moving anywhere.
"We are advising people to stay in their houses. If they are heading for the city, don't."
Meanwhile, in Cullybackey in County Antrim the roof of a bungalow in Brackley Heights burst into flames when it was hit by lightning.
Divisional Fire Officer Kevin Synnott said it was dealt with quickly.
He added: "We would appeal to the public that they contact the best placed public service to deal with incidents of flooding in homes and on the roads, unless of course there is a risk to life, where the Northern Ireland Fire Brigade would attend.
"The Fire Brigade cannot pump the water away and therefore can only serve the public where life is at risk at these incidents."