A suspicious substance found Tuesday in an envelope at the Jamaican Embassy was not hazardous, authorities said, as they reopened a street at Dupont Circle that had been closed for more than 90 minutes.

The closure of both lanes of the 1500 block of New Hampshire Ave. NW, where the embassy is located, caused lunch-hour backups near dozens of restaurants and businesses.

D.C. firefighters responded about 12:30 p.m. and reopened the street a short time after 2 p.m., said Brian Leary, a spokesman for the U.S. Secret Service. A D.C. fire department spokesman confirmed that the envelope contained white powder.