BEIJING — A Chinese dissident who wrote politically sensitive articles, including some criticizing the government's handling of a devastating earthquake, was formally arrested Friday on charges of allegedly possessing state secrets, a human rights group said.

Prosecutors in the southwestern city of Chengdu approved the arrest and charges against Huang Qi, founder of the human rights Web site 64Tianwang, said Nicholas Bequelin of Human Rights Watch.

The move comes as the government is tightening a clampdown on potentially embarrassing protests or complaints before the Beijing Olympics, which begin in less than a month.

Huang has long been one of China's most outspoken activists.

Since his release in 2005, Huang, who is in his mid-40s, has supported a wide range of causes from aiding families of those killed in the 1989 military crackdown on pro-democracy protests in Beijing, to publicizing the complaints of farmers involved in land disputes with authorities.

Rights groups have said Huang was detained June 10 after visiting areas affected by a powerful May 12 earthquake centered in Sichuan and writing about parents who lost their children.

They linked his disappearance to articles he posted criticizing the government's response to the magnitude-7.9 quake that killed almost 70,000 people.