Yemen's electricity company says protesting tribesman have blown up main pylons, cutting off power to the capital, Sanaa, for nearly a full day.

Security officials said Wednesday that repair teams have not been able to reach the damaged pylons because the tribesmen are blocking the way.

The officials said the tribesmen are protesting a death sentence that was ratified Tuesday against one of their members convicted of belonging to al-Qaida and killing security agents.

The officials said the military is threatening to use force if they don't clear the area. Sanaa, already short on power, was plunged into darkness.

The officials spoke on condition of anonymity because they were not authorized to speak to the reporters.