A group of at least four people stole a male victim's wallet and iPhone this afternoon in a mugging near the CTA Brown Line stop on Chicago Avenue, police said.

The victim, who was with a companion at the time, was seriously injured about 3:45 p.m. on the 300 block of West Chicago Avenue when he was attacked on CTA Brown Line property by four to six people, police said, adding that one of the attackers may have been a female.

Police and the Chicago Fire Department said the male victim, whose age and identity were not released, was taken in serious condition to Northwestern Memorial Hospital.

The suspects were last seen fleeing south on Franklin Street outside the station, police said.

No one was in custody this afternoon.

WGN-TV contributed.

chicagobreaking@tribune.com