CNN reports that U.S. crude oil futures briefly spiked over $5 a barrel in electronic trading late Tuesday on rumors that Iran had fired on U.S. Navy warships.

Crude gave up most of those gains according to one trader after reports of a confrontation were denied.

U.S. light crude for May delivery jumped $5.18, or about 8%, to $68.91 a barrel in electronic trading before giving back most of those gains to trade at $64.40 a barrel, $1.47 above Tuesday’s settle price on the New York Mercantile Exchange.

“We have no information at this time that an incident has taken place in the Gulf,” Gordon Johndroe, a spokesman for the National Security Council, said about reports of a confrontation between Iran and U.S. Navy warships.