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

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

Kathy Gannon, an AP correspondent who for many years was the news organization's Afghanistan bureau chief and currently is a special correspondent for the region, was shot twice and later underwent surgery. 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 attack came on the eve of nationwide elections in Afghanistan. The Taliban have vowed to disrupt Saturday's vote for a new president and provincial councils.

The two were traveling Friday in a convoy of election workers delivering ballots from the center of Khost city to the outskirts, in Tani district. The convoy was protected by Afghan security forces. They were in their own car with a translator and the AP freelancer.

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, the freelancer said. 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."

Afghan President Hamid Karzai expressed his deep sadness over Niedringhaus' death and the wounding of Gannon.

"These two AP journalists had gone to Khost province to prepare reports about the presidential and provincial council elections," a statement from Karzai's office quoted him as saying. It added that Karzai instructed the interior minister and the Khost governor to assist the AP in every way possible.

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.

Niedringhaus, who also covers sports events around the globe, has received numerous awards for her works.

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.

Niedringhaus started her career as a freelance photographer for a local newspaper in her hometown in Hoexter, Germany at the age of 16. She worked for the European Press Photo Agency before joining the AP in 2002, based in Geneva. She had published two books.

Gannon, 60, is a Canadian journalist based in Islamabad who has covered Afghanistan and Pakistan for the AP since mid-1980s.

She is a former Edward R. Murrow Fellow at the Council on Foreign Relations in New York and the author of a book on the country, "I Is for Infidel: From Holy War to Holy Terror: 18 Years Inside Afghanistan."

After the attack, Gannon underwent surgery in Khost. The operation was described as successful and Gannon's condition was said to be stable.

In the run-up to Saturday's vote, Afghan security and electoral officials have vowed not to let the Taliban and other militant derail the elections while conceding it is impossible to prevent the Islamic militants from waging acts of violence.

The militants have also increasingly been targeting Westerners. In recent weeks, the Taliban also have claimed responsibility for attacks in the capital, Kabul, against a luxury hotel, a foreign guest house, a Swedish journalist and a Lebanese restaurant popular with foreigners.

The 51-year old Swedish reporter, Nils Horner, had worked for Swedish Radio since 2001 as a foreign correspondent. He was killed by a shot in the head as he was reporting on Afghanistan's election on a street in Kabul in early March. It was a rare assassination of a foreigner in the capital. An extremist Taliban splinter group later claimed responsibility for his death.