A 17-year-old girl has been charged with stealing Mayor Michael Bloomberg's car and assaulting one of his personal employees, police said Friday.

A male suspect is still on the loose, said Capt. Frank Lomia of the police department in Hackensack, N.J., where the carjacking took place Wednesday morning.

A member of Bloomberg's personal staff, Gradimir Bosnjak, was beaten and forced out of the mayor's Lexus while parked, waiting to pick up another employee. Police say that the girl approached Bosnjak's window, and that moments later the male jumped into the passenger seat and punched him in the face.

The carjackers then sped away, authorities said. Police found the vehicle abandoned in nearby Fair Lawn, N.J., about two hours later.

The girl, whose name was not released because she is a juvenile, was described as a runaway from Phillipsburg, N.J.

She was charged late Thursday with aggravated assault and carjacking. The teen was also charged with theft because a briefcase, cell phone and digital camera belonging to Bloomberg's employee have not been found.

Lomia said Friday that the suspects initially approached Bosnjak because they needed money to get to Paterson, N.J., where they were staying.

"At first they wanted money from him, and then they thought this might be a way to get home, so they took his car," Lomia said.

Bloomberg was not involved in the incident. He employs a staff to take care of his personal matters and tend to his various homes.

His spokesman, Stu Loeser, said Friday that "the mayor thanks the Hackensack Police Department for their hard work."