New Delhi, Sep 18 (IANS): The Pakistan Taliban is to blame for the killing of Indian author Sushmita Banerjee in Afghanistan, the Indian government said Wednesday, describing this as "extremely distressing".

The external affairs ministry said a probe by the authorities of Afghanistan's Paktika province into the Sep 5 murder of the 49-year-old showed that the case was "taking a very disturbing turn".

"Things have evolved in the probe... While it was initially for us very distressing that an Indian woman was killed brutally, we now find that it is taking a disturbing turn," spokesman Syed Akbaruddin said.

"The governor of Paktika province has indicated to our ambassador that those who are involved in this, based on arrests made, seemed to be what he described as Pakistan Taliban...

"The indication is they were from areas beyond Afghanistan's borders. This is extremely distressing for us," the spokesman said.

He said India had left the probe into the killing to the Afghan authorities "in whom we have full confidence".

Afghan officials conveyed to India that six to seven people had been arrested in the case.

"We will follow this case with laser-like precision because this is something extremely disturbing," he added.

Government sources had said Sep 13 that the plan to kill the Bengali author was "hatched in Pakistan" and that three militants who worked with Akbar Musafir, the local commander of the Afghan Taliban in Paktika, were involved in the killing.

Banerjee had defied her family to marry Afghan businessman Jaanbaz Khan. In 1998, she wrote the bestselling memoir "Kabuliwalar Bangali Bou (A Kabuliwala's Bengali Wife)", offering a vivid description of the suffering of women under the Taliban -- and how she escaped from Taliban custody.

Last week, a Taliban group - Suicide Group of the Islamic Movement of Afghanistan - claimed responsibility for the killing.