A pair of supposed good Samaritans, one of whom may need eye surgery for an injury sustained in an alleged attack by three foreign teenagers at a Changning district subway station exit four days ago, are urging witnesses to come forward online to help build a case against the youngsters to see them deported.

One of the said Samaritans, Zhang Wei, a 30-something who works as a sales agent for a local software company with his colleague, the other reported Samaritan, a 28-year-old man, identified only by his surname, Gu, said Monday that they will not accept money from the teens' parents as justice.

"We're unwilling to give up pressing charges against the foreign teens in exchange for money," Zhang told the Global Times Monday. "When the parents arrived, they didn't even care to apologize for their children's behavior."

Local police confirmed Monday that the underage teens were later released to their legal guardians around 1 am on Saturday. It was several hours after Zhang and Gu spotted the teens beating an unnamed victim, a man from Jiangsu Province in his 20s, who they tried to help before being dragged into the attack.

Changning district police press officer Shen Qian said Monday that the minors were questioned, but could not be held longer. With their parents, the teens were escorted home, where they remain under "police control" as officers continue to investigate the case.

Before leaving the police station, however, the parents had agreed to compensate Zhang, Gu and the victim for their injuries, but the deal was quickly shot down, said Shen.

Zhang, a native of Hunan Province, said Monday that the teens should be deported back to their home countries to prevent them from hurting any other innocent passersby.

Blind-sighted by a narrow staircase at Beixinjing station along the Line 2 subway, Zhang said that he and Gu did not stand a chance against the "tall and bulky" teens, who he described as over 180 centimeters tall and further fueled by alcohol.

Local police, however, did not confirm Monday whether the teens had been drinking, disclosing only that they are all under the age of 18, and from the US, UK and Switzerland.

Gu had about 30 stitches to his eye after his eyeglasses were shattered in the attack, while a medical assessment issued Monday advised surgery.

Doctors at Shanghai No.9 People's Hospital, where Gu was treated, said that they were not authorized to speak publicly on the details Monday, but Zhang said that Gu risks "losing his eye."

As of last night, the appeal for witnesses on online forum tianya.cn had been viewed some 20,500 times.

Police press officer Shen said Monday that charges are pending a final medical report on the injuries Zhang, Gu and the victim suffered, which is expected to be out tomorrow.

The degree of the injuries to be outlined in the report will weigh heavily on the severity of the charges for the teens, according to Zhai Jian, a criminal lawyer and founding partner of Shanghai Zhaijian Law Firm.

"While it is unlikely they'll be deported over the incident, they could face criminal charges and that could mean up to three years in jail for each of them," he told the Global Times Monday. "But, since they're minors, it might not come to that."