From NBC Chicago:

In two separate incidents, as many as 15 teens have stormed Chicago Transit Authority buses, attacked their victims and darted off with cell phones and other electronic devices, authorities said Tuesday.

Both incidents were near the University of Illinois at Chicago campus, prompting city and campus authorities to issue community alerts.

In the first attack, near West Roosevelt Road and South Loomis Street at about 11:40 p.m. Saturday, a victim was struck multiple times before the thieves ran off with his cell phone.

About 25 minutes later, near South Racine Avenue and West 13th Street, a student said he was sitting on a No. 12 bus when as many as 15 black boys and young men boarded the bus without paying. The student was hit in the back of his head with a glass bottle and was robbed of his iPod, said UIC police.

An ambulance took the student to University of Illinois Medical Center for treatment, the alert said. Surveillance video from the bus may be available for review, it said.

The young thieves were described as being between 14 and 20 years old, standing between 5 feet, 5 inches and 6 feet, 1 inches tall, and weighing between 140 and 180 pounds. They were last seen wearing baseball caps, shorts and T-shirts. Some of them had braided hair and others had short hair, the alert said.

The community alerts come as other mob attacks in Streeterville and along the lakefront are making headlines. Five teens have been arrested in connection with the Streeterville attack, but police Supt. Garry McCarthy vowed to find more of them.

Anyone with information about the bus attacks should call Area 4 detectives at 312-746-8253.

Click here to read more from NBC Chicago.