The interior ministry statement said that security forces in the provinces of al-Jawf, Amran and Hajjah were now partaking in the search and that they were using "every means at their disposal to capture the kidnappers as soon as possible."

In addition, helicopters were reported to be flying above the province of Saada on Wednesday in search of the hostages and their kidnappers.

No way out

The ministry added that police forces had closed all roads leading to Saada to prevent the kidnappers from transporting the hostages.

"No place would be excluded in the pursuit of the kidnappers and murderers even if they are in the depths of the earth," the statement said.

Yemenis protest abduction

Meanwhile, witnesses are reporting that thousands of Yemenis took to the streets of Saada on Wednesday to protest the kidnappings and demand the immediate release of the six remaining hostages, which include a German technician, his wife and their three children, and a British engineer.

In total, nine foreign aid workers, including seven Germans, were kidnapped last Friday in the Saada province near the Yemen Saudi Arabia border.

Three of the abductees, two German nurses and a Korean teacher, were found Monday in a dry river bed 12 km northeast of Saada. Reports say they had been killed with pistols and daggers.

President Ali Abdullah Saleh has offered a $250,000 (180,000 euros) reward for information on the whereabouts of either the kidnappers or the hostages.

glb/dpa/AP

Editor: Susan Houlton