Authorities in the US state of Connecticut are investigating a possible threat against President Obama, according to local media reports.
A statement from the US Secret Service, which oversees the President's personal security, said: "Information has been received by law enforcement regarding a potentially suspicious person and vehicle. We are working with our local law enforcement partners to determine the validity of the information provided."
A local newspaper said state police were looking for a man who had allegedly made a threat against Obama.
He was believed to have been driving a car with Connecticut licence plates.
Obama was making a number of fundraising appearances in the north-east of the country on Friday.
More top news
A man in a panda onesie has been shot after allegedly making a bomb threat against a television station.