A Metrobus passenger was stabbed Wednesday evening in Northeast Washington, D.C. police said.

The assault happened near the intersection of 11th and H streets just before 6 p.m, said Officer Hugh Carew, a D.C. police spokesman. Police found the wounded man conscious and breathing, and he was taken to a hospital in serious condition.

Metro officials said the adult male was stabbed twice in the chest by another man aboard an X2 bus that was headed to Lafayette Square.

It was not immediately clear what prompted the attack.

Police said the suspect is a dark-complexioned black man who is about 5’8” tall and weighs about 200 pounds, with a bald head and a beard. He was last seen wearing a black hat, black sweatpants and carying a black bag, Carew said.

Dana A. Hedgpeth contributed to this report.