Yemeni forces loyal to entrenched president Ali Abdullah Saleh have faced off with opponents in a gunbattle that left six people dead, medical sources said.

Monday’s violence in the capital, Sanaa, erupted a day after the president backed out of a deal brokered by the Gulf Co-operation Council (GCC) to step down.

Medical officials said at least six people died and dozens were injured after supporters of Sheikh Sadiq al-Ahmar, a powerful tribal leader who has sided with anti-government protesters, clashed with police.

“There is heavy gunfire and violent clashing between government forces and Sheikh [Sadiq] al-Ahmar’s guards,” a witness said.

The clashes cast further doubts on the prospects for an end to a three-month crisis in which youth-led demonstrators – inspired by protests that toppled long-serving presidents in Tunisia and Egypt – are demanding an end to Saleh’s nearly 33-year rule.

SABA, the state news agency, reported that one of the wounded was a journalist while Al-Yemen state TV said more than 200 journalists were trapped inside the state news agency’s building.

The government accused al-Ahmar’s men of firing on a school and the SABA building. Al-Ahmar’s office said government forces opened fire when his guards prevented them from entering a school where Ahmar said loyalists were stockpiling weapons.

Remaining defiant

The shooting, which shattered windows at SABA’s offices, followed the collapse of a transition deal that Saleh was to have signed on Sunday and that would have given him immunity from prosecution, ensuring a dignified exit.

Saleh backed out of the GCC-sponsored deal for a third time, a day after the opposition signed it on Saturday. The deal would offer him a period of 30 days to step down and grant him immunity from prosecution.

The gunbattle on Monday came as Hillary Clinton, the U.S. secretary of state, accused Saleh of turning his back on his commitments.

Clinton urged Saleh to sign the U.S.-backed agreement in order to prevent further chaos that has consumed Yemen, already battling a secessionist movement in the south, an armed rebellion in the north and al-Qaeda in at least three provinces.

The U.S. embassy in Yemen shut its consular section to the public on Monday, saying the move would be for at least two days due to the violence.

Meanwhile, south of the capital, loyalist gunmen opened fire on the headquarters of the Islamist party Islah, the biggest member of Yemen’s opposition coalition, in the city of Ibb.

Before the gunbattle, loyalist gunmen had trapped Western and Arab diplomats in the United Arab Emirates embassy for hours.

Inside were the head of the GCC, Abdullatif al-Zayani, who has spearheaded mediation efforts, and the U.S. and several European ambassadors. The GCC brings together six nations – Bahrain, Kuwait, Oman, Qatar, the United Arab Emirates and Saudi Arabia.

The mediators were effectively blocked from heading to the presidential palace where the now failed deal was to be signed.

They had to later be flown out by helicopter. Gulf neighbours subsequently withdrew their initiative, citing a “lack of suitable conditions”.