MANILA, Jan. 16 -- Twelve of the 28 Chinese arrested by Philippine Immigration Bureau officials Wednesday in a raid at a shopping mall in Metro Manila have been released as of Thursday, the Chinese embassy in Manila said.

Philippine Immigration Bureau (BI) officials launched a raid at Baclaran Terminal Plaza Mall in Pasay city, Metro Manila, on Wednesday afternoon, seizing 28 Chinese on alleged overstaying and undocumented working, and took them away for identity authentication.

In the course of investigation, two were confirmed as Chinese- Filipinos and released on the same day. Ten Chinese nationals with all required documents were freed on Thursday. The remainders are still under investigation, according to the Chinese embassy.

Upon receiving report of the case, the Chinese embassy immediately sent its representatives to the venue and verify details of the case with Philippine immigration officials, said Zhang Hua, spokesman of Chinese embassy.

He said the embassy is closely following the development of the case and urged the Philippines to properly handle the issue as soon as possible, while providing necessary consular protection and service for those arrested.

This was the second raid by BI officials at shopping malls where Chinese traders gathered in little more than a month.

On Dec. 11 last year, 77 Chinese nationals were also arrested by BI officials in two shopping malls in Manila's China town in an abrupt operation. After going through investigation, 72 of the detainees were released.