PORTLAND — Portland police are investigating an assault that sent one man to Maine Medical Center with unknown injuries.

Lt. Gary Hutcheson said the man was assaulted in the vicinity of 98 India St. around 8 p.m. Sunday night.

Hutcheson said police would not be releasing a description of the suspects because the assailants are known to police.

He said the case has been turned over to the department’s Criminal Investigation Division. No other details were available Sunday.