Shots have been fired near the house of the US Vice-President Joe Biden.
A US Secret Service official told CNN multiple gunshots were fired from a vehicle that drove at high speed past the Biden residence in Greenville, Delaware, late on Saturday night local time.
Mr Biden and his wife Jill were away at the time.
Searches were due to be conducted outside the home and nearby residences in New Castle County to see if any buildings were hit by bullets, CNN said. The vice president's residence is several hundred yards from the main road from where the shots were fired.
Mr Biden's office says the vice-president and his wife were later briefed on the incident.
"The Secret Service is working closely with the New Castle County Police," Secret Service spokesman Edwin Donovan is quoted by The New York Times as saying.
- BBC / Reuters