Journalist and activist Wu Wei, a former Beijing based reporter for the South China Morning Post, reportedly arrested by Beijing police, has not been heard from by family or friends for several days. Several Hong Kong media outlets reported the arrest, based on messages published on the Weibo social network, then relayed by journalist and blogger Wen Yunchao. No information has been released on why she would have been arrested. But the action may stem from her support for the release of human rights advocate Pu Zhiqiang. Reporters Without Borders demands an immediate explanation from the Beijing government. The news followed by one day the arrest of Xiang Nanfu, a regular contributor to the Boxun news website. Several days before that came an official announcement that journalist Gao Yu had been placed in criminal detention. She has not been heard from for more than one week. "As in the case of Gao Yu, the fact that a committed journalist such as Wu Wei has not been heard from is of the utmost concern," said Benjamin Isma��l, head of the press freedom organization's Asia-Pacific desk. "All the more so because the police are stepping up the pace of kidnap-style arrests as the anniversary of the Tienanmin Square events approaches." Isma��l added: "In the absence of charges against her, we demand that Wu Wei be released immediately." Information concerning the journalist's arrest had circulated on 13 May on Weibo. But, at her family's request, word of the detention did not immediately circulate more widely. In the run-up to the 25-year anniversary of the Tian'anmen massacre, arrests of dissidents and censorship operations are on the increase in China. The country is ranked 175th out of 180 countries in the 2014 Reporters Without Borders World press freedom index.