News photographer Anja Niedringhaus killed by Afghan police officer

One woman was killed and the other critically injured in the attack, which took place ahead of the country's presidential elections

German photographer Anja Niedringhaus, 48, was killed instantly (AP)

Two female foreign journalists have been shot in eastern Afghanistan, officials have said.

A veteran Associated Press photographer was killed and an AP reporter was wounded in the attack on Friday, when an Afghan policeman opened fire while they were sitting in their car in eastern Afghanistan.

The incident took place on the eve of presidential elections on Saturday - Taliban insurgents have pledged to disrupt the polls through a campaign of bombings and assassinations.

Anja Niedringhaus, 48, an internationally acclaimed German photographer, was killed instantly, according to an AP Television freelancer who witnessed the shooting.

Kathy Gannon, the reporter, was wounded twice and is receiving medical attention. She was described as being in stable condition and talking to medical personnel.

“Anja and Kathy together have spent years in Afghanistan covering the conflict and the people there. Anja was a vibrant, dynamic journalist well-loved for her insightful photographs, her warm heart and joy for life. We are heartbroken at her loss,” said AP Executive Editor Kathleen Carroll, speaking in New York.

The two were traveling in a convoy of election workers delivering ballots from the centre of Khost city to the outskirts, in Tani district. The convoy was protected by the Afghan National Army and Afghan police. They were in their own car with a freelancer and a driver.

According to the freelancer, they had arrived in the heavily guarded district compound shortly before the incident.

As they were sitting in the car waiting for the convoy to move, a unit commander named Naqibullah walked up to the car, yelled “Allahu Akbar” - God is Great - and opened fire on them in the back seat with his AK-47. He then surrendered to the other police and was arrested.

Medical officials in Khost confirmed that Niedringhaus died.

In a memo to AP staff, AP President Gary Pruitt remembered Niedringhaus as "spirited, intrepid and fearless, with a raucous laugh that we will always remember."

"Anja is the 32nd AP staffer to give their life in pursuit of the news since AP was founded in 1846," he wrote.

"This is a profession of the brave and the passionate, those committed to the mission of bringing to the world information that is fair, accurate and important. Anja Niedringhaus met that definition in every way."

Niedringhaus covered conflict zones including Kuwait, Iraq, Libya, Gaza and the West Bank during a 20-year stretch, beginning with the Balkans in the 1990s. She had traveled to Afghanistan numerous times since the 2001 U.S.-led invasion.

She was part of an AP team that won the 2005 Pulitzer Prize in breaking news photography for coverage of the war in Iraq, and was awarded the Courage in Journalism Award from the International Women's Media Foundation. She joined the AP in 2002 and had since been based in Geneva, Switzerland. From 2006 to 2007, she was awarded a Nieman Fellowship in journalism at Harvard University.

Gannon, 60, is a Canadian journalist based in Islamabad for AP. She has covered war and unrest in Afghanistan and Pakistan for three decades.

Last month, a prominent Afghan journalist with the Agence France-Presse news agency was killed alongside eight other people when Taliban gunmen opened fire inside a heavily fortified luxury hotel in the centre of the capital, Kabul.

Additional reporting by agencies