Kabul - Gunmen shot dead a woman journalist in the north of Afghan capital Kabul, the second such killing in less than a week, officials said on Wednesday.

Zakia Zaki, who also served as headmistress of a school in Parwan province, ran a private radio station, partially funded by a Western media group.

The 35-year-old married woman was killed at her house late on Tuesday night.

Zaki was threatened recently by some local commanders to shut down the station or face death, the head of Afghanistan's Independent Journalist Association said.

"She believed in freedom of expression, that's why she was killed," Rahimullah Samander told Reuters.

Authorities said an investigation had been launched to find

out who killed Zaki, seen as an outspoken and courageous journalist.

Her killing follows the murder of Sanga Amach, a news presenter for a private television station, at her house in Kabul last Friday.

Authorities say they have arrested some suspects in connection with Amach's murder. She had also been ordered by unidentified people to stop her work.

Independent media has flourished in Afghanistan following the fall of the Taliban in 2001 as dozens of foreign funded radios and private television channels have opened.

Many channels run largely entertainment programmes and some of their programmes are seen as too modern in the deeply conservative nation.