A Vietnamese rights group says the mother of a prominent jailed blogger has died after setting herself on fire in protest of her daughter's detention. Self-immolation is a rare act of dissent in Vietnam, whose Communist leaders exercise tight control over society.

The Vietnamese Redemptorist News network says the mother, Dang Thi Kim Lieng, set fire to herself Monday morning near a local government office in the southern city of Bac Lieu.

The Christian organization says the woman, a Catholic, died of her injuries while being taken to a hospital. Her daughter, Ta Phong Tan, is one of three Vietnamese bloggers facing trial on charges of conducting propaganda against the ruling Communist party.

The VRN network advocates for the rights of Vietnamese Redemptorists, a branch of the Roman Catholic Church.

Vietnamese citizen journalists say the trial of the three bloggers is due to begin in Ho Chi Minh City August 7, after being delayed for several months. The bloggers are founding members of the Club for Free Journalists, a group that promotes freedom of expression and independent journalism.

Ta Phong Tan is a former policewoman who began working as a freelance journalist in 2004 and started her own Justice & Truth blog in 2006, writing hundreds of articles about social problems and official corruption. Authorities arrested her last September and have kept her in detention since then. She is in her mid-40s.

Her mother's self-immolation is the first such protest to be reported in Vietnam since the 1970s.