Two German men have been missing in Afghanistan since last Friday, prompting German Foreign Minister Guido Westerwelle to assert the possibility that they may have been kidnapped.

"Two German citizens are missing and I cannot rule out the possibility that they are the victims of a kidnapping," Westerwelle said to the Associated Press.

The men, who were said to have been working for an unnamed aid organization, traveled through Kabul’s Salang Pass and into the mountains, telling their driver they would return that same day at 4 p.m. At 6 p.m., when the pair had not returned, the driver reported their disappearance to local authorities.

"Since 6 p.m. Friday evening, we have been searching—jointly with Afghan security forces—but we have not been able to find them,” said General Sher Ahmad Maladani, police chief of Afghanistan's northwestern Parwan province.

Maladani did not rule out the possibility that the men may have run into other problems.

"It is not a Taliban area," he said. "It is one of the safest areas of Afghanistan, but there are other possibilities. These mountains are very high. Maybe they lost their way. Wild animals are another issue in these mountains and maybe they were attacked by animals. There is no one to ask."