Police opened an investigation into the abduction but did not say who they thought was responsible.

Yemen’s Journalist Syndicate said the kidnappers might be tribesmen angered by Shai’s reporting on the relationship of some tribes with the Yemeni wing of the militant group Al-Qaeda.

Analysts say Al-Qaeda members, many of whom are holed up in Yemen’s most impenetrable mountains and deserts, often receive protection from local tribes.

“We don’t know for certain who is behind the incident but we fear it could be a tribal group... because of his analyses of the tribes’ sympathy for Al-Qaeda. That is why his life is in danger,” a Syndicate member said, asking not to be identified.

Yemen, which borders Saudi Arabia, leapt to the forefront of Western security concerns after a Yemen-based regional wing of Al-Qaeda claimed responsibility for a failed attempt to bomb a US-bound airliner in December.

The conflict between the impoverished country’s government and Al-Qaeda is intensifying, and tribes are increasingly drawn into the fighting.

In June, the Yemeni Army shelled militant targets and fought gun battles in the Al-Qaeda stronghold of Wadi Obeida in Maarib province, the source of much of the country’s oil.