Two female Japanese tourists were kidnapped Wednesday by unknown assailants in Yemen's Marib province east of the country's capital of San'a, a Yemeni security official and a tribal leader said.

The official and the tribal leader said the Japanese women were visiting a historic dam in the town of Marib, when they were seized by unknown armed men. Both the official and the tribal leader spoke on condition of anonymity because they were not authorized to talk to the media.

According to the official, the kidnappers shot at Yemeni soldiers accompanying the tourists and wounded one of them before they seized the two Japanese women and sped away in a car.

The two Japanese were part of a larger group of tourists but were a little bit away from the others, which enabled the assailants to pick them as targets, the official added.

Marib is located 109 miles east of San'a. Last month, a bombing at a military checkpoint near the site of the kidnapping killed three Yemeni soldiers and injured four.

Yemeni tribes have in the past taken several foreigners — either tourists or foreigners residing or working in the country — as hostages, to pressure the government for demands that spanned from freeing clan members from jail to improving roads, hospitals and schools in their area. It was not clear if the kidnappers Wednesday were also tribesmen.

In most cases the kidnappings were resolved and the hostages freed.

Yemen is the poorest country on the Arabian peninsula. It is a key U.S. ally in the Middle East, but it also is the ancestral homeland of Usama bin Laden's family and Al Qaeda loyalists are active in the country.

In January, suspected Al Qaeda militants opened fire on a convoy of tourists in a remote desert mountain valley in northern Yemen, killing two Belgian women and their Yemeni driver.

In July 2007, a suicide bomber in an explosives-packed car attacked tourists visiting a temple in central Yemen, killing eight Spaniards and two Yemenis. Yemeni authorities also blamed that attack on an Al Qaeda cell.