Maryland Transit Administration officials are investigating two fights in which bus drivers allegedly helped carry out the attacks.
In one of the incidents, in June, a 9-year-old boy was allegedly maced, according to the MTA.
On August 22, two passengers got into a fight over a vacant seat on a bus in Dundalk, after which the bus driver allowed the suspect back onto the bus after the fight, according to a police report.
The victim told police he was getting off at Holabird Ave. and Delvale Road stop, and suspect yelled at him, prompting him to push the suspect. The suspect them struck him in the face several times outside the bus.
After the fight, the driver then allowed the suspect to get back on and drove off, MTA officials said. They identified the driver as Qwanda Joines. Joines has not been charged in the incident, according to court records.
Joines has been "withheld from service pending the outcome of the investigation," the MTA said, but would not elaborate or say whether she is being paid.
On June 6, six juvenile passengers on a bus in the 1200 block of West 41st Street in Baltimore allegedly assaulted a man, a woman and a 9-year-old boy about 3:30 p.m. outside the vehicle, MTA officials said.
The incident allegedly occurred after the adult victims had gotten into a "verbal confrontation" with the bus driver, MTA officials said.
The man, identified as Christopher Fisher, was allegedly maced and attacked; the woman, identified as Kristina Gibson, was "pulled to the ground by her hair and repeatedly assaulted," and the boy was maced and pushed, the MTA said.
All of their injuries were minor, the MTA said.
The bus driver, identified as Karen Murphy, "allegedly failed to render aid, call for assistance and aided in the fleeing of the suspects by advising them to re-board the coach," the MTA said.
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Murphy has been charged with six counts of assault, court records show. She was terminated, MTA officials said. The six juveniles involved in the attack, who have not been identified, have also all been arrested and charged with assault, the MTA said.
One of the juveniles is 17 years old; the other five are are 16 years old.
"The safety and security of our customers is our number one priority. Anyone who jeopardizes this core principle will no longer work for the MTA," MTA Administrator Robert Smith said in a statement.
MTA officials and police continue to investigate these incidents.