Violence erupted in the Yemeni capital as security forces attempted to clear a sit-in by Houthi rebels blocking a main road leading to the airport as part of a campaign against the government.

A spokesperson for the Houthi movement told Al Jazeera that one protester was killed and another five injured on Sunday as police tried to disperse a crowd that had camped near the interior ministry in Sanaa.

The violence marks the latest escalation in three weeks of demonstrations by tens of thousands of Houthis calling on the government to resign and fuel prices to be cut.

Anti-riot police hurled tear gas canisters and deployed water cannons against the rebels who blocked traffic coming into the capital from the south and west.

The interior ministry told Al Jazeera security forces moved in after the protesters failed to move from a busy road leading to the city's international airport.

Security officials accused the rebels of attacking troops, as witnesses reported protesters commandeering a bulldozer, a water cannon truck and an armoured vehicle.

Al Jazeera's Hashem Ahelbarra, reporting from Sanaa, said there was concern in the capital that any fighting between the police and the Houthis could force the rebels to call in further reinforcements.

Civil disobediance 

The rebels, also known as Zaidis or Ansarullah, had pitched new tents blocking access to the ministries of electricity and telecommunications on Airport Road, as part of a new "civil disobedience" campaign against the government.

The Houthis have been pushing for the government of President Abd-Rabbu Mansour Hadi to resign, accusing it of corruption.

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A source close to the presidency told the AFP news agency that the Houthis had submitted a list of demands, including the president "consult with them on naming the new prime minister" and the ministers of defence, interior, foreign affairs and finance.

The demonstrators, who carried portraits of Syria's embattled President Bashar al-Assad and Lebanese Shia group Hezbollah's Hassan Nasrallah, wore yellow bands on their wrists and across their foreheads as a "warning" to authorities.

Authorities in Sunni-majority Yemen accuse Iran of backing the Shia rebels, and Hadi on Saturday urged Tehran to be "reasonable" in dealing with his country.

Banners at the sit-in said protests would "continue until the fall of the Muslim Brotherhood government" a reference to the Sunni al-Islah (Reform) party.

The president has urged the Houthis to join a unity government, a plan the rebels have rejected.

Yemen has been locked in a protracted transition since long-time President Ali Abdullah Saleh was forced from power in February 2012 after a deadly 11-month uprising.

Source: Al Jazeera and agencies