HANOI, Vietnam - A Vietnamese blogger who criticized the Communist Party's policies has been detained by police, his close friend said Monday, days after another popular blogger was fired from his job at a state-controlled newspaper.

Bui Thanh Hieu, who writes his blog under the pen name "Nguoi Buon Gio" or "Wind Trader," was taken into police custody in Hanoi on Thursday, said a close friend, speaking on condition of anonymity for fear of reprisal.

The friend said that on Sunday she talked to Hieu's wife, Lien, who said she spoke briefly to her husband while he was in the police station Thursday. Lien recounted coming home from work that day and finding the television and fan on but her husband gone, the friend said.

Police seized three laptops and documents from his home in Hanoi and also searched his parents' house, the friend said.

Police declined to comment.

Hieu's postings have been critical of the ruling Communist Party's handling of its relations with neighbouring China and land disputes with the Roman Catholic Church. Hieu, 37, has also criticized a controversial government-backed bauxite mining project in Vietnam's central highlands.

The detention of Hieu came several days after one of Vietnam's most popular and boldest bloggers, Huy Duc, was fired by the Saigon Thiep Thi newspaper after the Communist Party complained about writings on his blog "Osin."

Hieu's detention is the latest in a string of arrests in Vietnam's latest crackdown on dissent. In June, human rights lawyer and pro-democracy activist Le Cong Dinh and four others were arrested for working with "hostile forces" against the state.

Hieu was interrogated by police repeatedly in 2008 and 2009 about his political activities, his friend said, questioning that began after his participation in an anti-China demonstration. Police pressure on his business partner also caused him to lose his job and his investment.

Earlier this year, the government tightened its rules for bloggers, requiring that they must restrict their writings to personal matters.

A blogger known as Dieu Cay was charged with tax evasion and sentenced to 30 months in jail after encouraging people to protest at the Olympic torch ceremonies in Ho Chi Minh City shortly before last summer's Beijing Olympics. He criticized China's policies in Tibet and the Spratly islands.