SANAA, Yemen (AP) -- Military and security officials say the Saudi-led coalition fighting Shiite rebels in Yemen has doubled its near-daily attacks in the central province of Marib and the adjacent border area of al-Jawf, preparing a push into the rebels' northern strongholds.
There was no immediate word on casualties from Monday's airstrikes.
The officials, speaking on condition of anonymity because they are not authorized to brief reporters, said their Marib forces have also received major reinforcements, including hundreds of Saudi-trained troops, ambulances and armored personnel carriers manned by Saudi and Emirati soldiers.
They say the force aims to take Saada, the main northern stronghold of the rebels known as Houthis.
Backed by coalition airstrikes, pro-government forces have recently pushed the Houthis out of several key areas in the south.