Hani Mohammed, File, Associated Press
In this Monday, Aug. 18, 2014 file photo, Yemeni Shiite groups march during an anti-government demonstration in Sanaa, Yemen. Yemeni security forces said Sunday, Sept. 7, 2014 that they have moved with tear gas, water cannons and bulldozers to clear a sit-in held by Shiite rebels blocking the capital's airport road. The rebels, known as Hawthis, have been camping out for nearly three weeks in the capital, protesting against the government and calling for the reinstatement of fuel subsidies.

SANAA, Yemen — Yemeni security forces moved to break up a sit-in held by Shiite rebels blocking the capital's airport road on Sunday, using water cannons, bulldozers and tear gas, security officials and witnesses said.

The rebels had earlier escalated their weekslong anti-government protests by moving to the road leading to the strategic airport, setting up tents near the Communications Ministry and blocking traffic into Sanaa from the south and west.

Security officials said protesters pelted the troops with rocks. One eyewitness said protesters commandeered a bulldozer, a water cannon truck and an armored vehicle from security forces.

The witness said one protester snatched a machine gun from one of the soldiers on an armored vehicle near the Interior Ministry, also on the airport road. Troops fired several warning shots in the air.

After brief clashes, security forces pulled back to the nearby Interior Ministry, while protesters rebuilt some of the fallen tents. Government and security officials said high-level talks between the rebels, known as Hawthis, and the authorities were ongoing to calm the situation. The Hawthis could not be immediately reached for comment.

Other sit-ins remain in place around Sanaa near several government ministries. Armed Hawthis have moved from their stronghold in the northern Sadaa province to the outskirts of the capital in recent days to support them.

The officials spoke on condition of anonymity because they are not authorized to speak to the media.

The Shiite rebels have been camping out for nearly three weeks in Sanaa, demanding the government resign and reinstate fuel subsidies.

But when Yemeni President Abed Rabbo Mansour Hadi dismissed his Cabinet on Tuesday and promised to appoint a new premier within a week in a move to offer concessions, the rebels' only escalated protests.

Fuel prices nearly doubled after the subsidy cuts, but the reaction on the street was limited when it was announced in July. Opponents say the Hawthis are using the issue as a cover and are really just want to seize power.

The Hawthis waged a six-year insurgency that officially ended in 2010. The following year, the country was convulsed by an Arab Spring-inspired uprising that eventually forced longtime President Ali Abdullah Saleh to step down as part of a U.S.-backed deal that gives him immunity from prosecution.