BEIJING, Nov. 6 (Xinhua) -- Chinese pop singer Zang Tianshuo has been formally arrested by Beijing police for suspected mobbing, the Beijing Public Security Bureau said on Thursday.

    The bureau's information office said that Zang had been in police custody for some time, that the case would be soon transferred to the procuratorate, meaning that the police investigation has been closed.

    Zang, a household name in China, is one of China's first rock musicians. He has written many hit songs such as "Friends" and a number of movie and advertising songs. He was voted as the most popular mainland singer/songwriter at the 9th Chinese Music Awards in 2003.

    Police sources who declined to be named said Zang was detained on September 28.

    They said police investigation had taken quite some time because the case was complicated and involved criminal gangs.