Bomb disposal experts were called to a Wearside street after an explosive went off under a parked car.
A "crude, homemade improvised device" damaged a car in Compton Court, Oxclose, Washington, in what police believe was a "targeted incident".
Police were called out at 11.20pm last night after residents heard a loud bang.
They found that a suspected improvised explosive device had been placed under the rear side of a car in the street, which was damaged as a result of the bang.
An Explosive Ordinance Disposal team visited the street today to ensure the devise is safe.
Compton Court resident Samantha Hyson, a 30-year-old mum-of-two, said: "We heard two loud bangs at about 10.30 last night and we thought it was a bit late for people to be setting fireworks off.
"We could tell how close they were because of how loud it was, but didn't think anything more of it and went to sleep.
"Then when we woke up this morning, the street was cordoned off and there were a lot of police here, including forensics and a bomb disposal unit.
"We saw them tow a car away but it was covered with a blue sheet so we couldn't tell what car it was.
"The police were here for much of the day until about 4.30pm. There's quite a lot of cars in the street so we didn't think it could be an accident, we thought it must be deliberate.
"It's surprising because we usually don't have any bother in the street."
Supt Brad Howe said: "We do believe this may have been a targeted incident and at this time, we haven't received any further reports.
"Enquiries are ongoing and officers are in the area to provide reassurance to residents.
"We believe this to be a crude, homemade improvised device, which has caused only minimal damage to the vehicle, however we are taking this very seriously and would appeal to anyone with any information to contact police.
"We ask anyone who may have been in the area at the time or witnessed any suspicious behaviour to come forward.
"Our officers will remain in the area for reassurance should you have any concerns, please speak to an officer."
Anyone with any information can contact police on 101 quoting 1049 071116 or independent charity Crimestoppers anonymously on 0800 555111.