Singer Gavin DeGraw was recovering in a New York hospital on Tuesday with concussion and a broken nose after apparently being attacked by three men and hit by a taxi cab.
Police said they were investigating an assault by three males in the city's East Village in the early morning hours on Monday, but said it was unclear what led to the attack.
"The victim claims to have been struck by these individuals and taken to hospital," a police spokesman said. Police would not comment on whether DeGraw had been drinking.
The 34-year-old singer also reported having been struck by a taxi soon after the assault. He had just left a group of friends when the attack took place. No arrests have been made and no motive has emerged for the assault.
The New York singer, whose hits include "I Don't Want to Be" and "Chariot," was suffering from "a concussion, broken nose, black eyes, cuts and bruises," and is in stable condition his publicist said.
DeGraw has been the opening act for the first leg of rock bands Train and Maroon 5's U.S. tour and was next due to perform on Tuesday.
"We have no information yet regarding his upcoming concert dates and promotion for his new album," said his publicist. "Gavin and his family appreciate everyone's concern at this time."
DeGraw got his start playing in nightclubs in and around Manhattan and hit it big when "I Don't Want to Be" was chosen as the theme song for television drama, "One Tree Hill."