By: Our Correspondent

Chinese authorities should clarify the whereabouts of two Chinese
journalists who reported on detained artist and social commentator Ai Weiwei, the Committee to Protect Journalists said today.

The detention of the journalists came as Chinese officials warned off foreign nations against pushing Ai Waiwai’s case forward.

issue is under investigation and the outside should not comment on this
issue habitually," Forreign Ministry spokeswoman Jiang Yu told
Agence-France Press. "We hope that the outside can respect China's
judicial sovereignty and judicial authorities handling the issue in
accordance with the law."

At the same time, the US-based online
petition website reported that its petition seeking Ai’s
freedom has been under sustained directed denial of service (DDS)
attack, presumably by Chinese hackers.

Family and colleagues have
been unable to reach Caijing magazine journalist Zhang Jialong since
the evening of April 28, according to Radio France Internationale. He
was believed to have gone for a "talk" with Beijing police, but no
notice of formal detention has been issued, RFI reported. Interrogations
are informally referred to as "chatting" or "drinking tea" with police
or security officials. The Global Post website posted a link to an online missing notice
issued by Zhang's family. Zhang, a 23-year-old intern, had reported on a
contaminated milk activist, Zhao Lianhai, and on Ai, the notice said.
Zhang had also actively discussed recent detentions on his Twitter
account, according to RFI.

Freelance journalist and documentary filmmaker Wen Tao has been missing and believed detained since April 3,
when he was taken away by officials in plainclothes shortly after Ai.
Wen, a former Global Times journalist and also an active Twitter user,
had been documenting Ai's work; his whereabouts and legal status are
unknown, according to international news reports.

disappearance of two journalists who were reporting on Ai Weiwei and
other Chinese activists is deeply concerning," said CPJ Deputy Director
Robert Mahoney. "We fear they are the latest victims of the Chinese
Communist Party's efforts to stifle the flow of independent

Chinese authorities have detained
a series of journalists and online commentators since anonymous calls
for anti-government demonstrations appeared on Chinese-language websites
in February, inspired by unrest in the Middle East and North Africa.
Some of those detained, such as online writer Ran Yunfei, now face criminal prosecution. Many others, like Zhang Jialong and Wen Tao, have simply disappeared. Internet censorship has tightened since the crackdown, which has also extended to professional Chinese journalists, ethnic minority websites, and the foreign press, according to CPJ research.

Contributed by the Committee to Protect Journalists