By CBS3 Staff

PHILADELPHIA (CBS) — The mother of a victim spoke exclusively to Eyewitness News as Philadelphia police announce charges of ethnic intimidation after a disturbing, violent assault was caught on camera.

The mother is heartbroken and furious over the attack of her 14-year-old son. She believes the attack was racially motivated.

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Name-called and punched.

Cellphone video shows a freshman Central High School student, who is of Asian descent, being attacked on the Broad Street Line subway while heading home from school Wednesday afternoon near Erie Station.

The video then shows a senior Central High School student, who’s also of Asian descent, trying to intervene, but she is thrown to the floor and then kicked and stomped on.

Her uncle talked exclusively to Eyewitness News, saying she wanted to protect the younger student.

“Stood up for him, helping the four Asian boys,” Mike Lu said. “Saying ‘stop it.'”

A source tells Eyewitness News some of the attackers are from a charter school. A source also says the parent of one of the attackers came forward to police after seeing the video.

The district attorney has charged four juveniles in the assault. Each has been charged with aggravated assault, ethnic intimidation and other related charges.

The freshman boy’s mother also talked Eyewitness News. Chinese is her first language, so her friend, Jack Chao, translated.

“We are the city of love, we are not the city of hate, and her kid didn’t do anything wrong, and her kid didn’t even know the girls,” Chao said.

The boy’s mother said it was “discrimination,” Chao said.

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SEPTA police agree and say four girls ages 13 to 16 have been identified as the suspects in the attack.

“This was an attack based on ethnicity and ethnic slurs were used by the attackers,” SEPTA Police Chief Thomas Nestel said.

Meantime, a group of Asian American parents met with the principal of Central High School Wednesday. Only Eyewitness News captured the parents leaving, many feeling frustrated.

“They rely on the subway to go to school and come back from school,” parent Mei Liu said. “because that’s their only transportation.”

“Where are the uniformed, visible, law enforcement officers to address what is a continuing situation?” City Councilmember David Oh said.

SEPTA Police will provide escorts for Central and girls high school students on the subway.

In all, police say four Asian students were attacked. One of the students involved was readmitted to the hospital Thursday night.

City Councilmember Helen Gym agrees. She met with members of Asian Americans United Thursday morning, where more than 300 people joined to discuss their concerns.

“One of the things that was raised was escalating anti-Asian violence incidents that are happening all over the city,” Gym said.

Gym says those incidents have been ranging from slurs — that even she’s received — to physical acts of violence.

“Anti-Asian sentiment and anti-immigrant sentiment is being perpetuated even in the City of Brotherly Love and this is an important time for people to have a greater sense of compassion,” Gym said.

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CBS3’s Matt Petrillo and Jasmine Payoute contributed to this report.