Fierce Clashes near Yemen Capital Airport, Flights Diverted

Heavy clashes between Yemeni tribesmen and elite Republican Guard troops on Wednesday prompted the closure of the capital Sanaa's airport and the diversion of flights, aviation and tribal sources said.

"Sanaa's airport has been shut down and flights have been diverted to the airport of Aden," the southern regional capital, the official said.

Tribal sources said that heavy fighting erupted near the airport between Republican Guard troops and tribesmen belonging to Arhab, the tribe of hardline cleric Abdul Majid al-Zindani, who has been sanctioned by Washington as a "terrorism financier."

U.S. President Barack Obama on Wednesday repeated his call for Yemen's leader Ali Abdullah Saleh to quit as clansmen loyal to a powerful opposition tribal chief seized buildings and battled security forces in Sanaa.

"We call upon President Saleh to move immediately on his commitment to transfer power," Obama said at a joint press conference with British Prime Minister David Cameron in London.

Three days of fighting has killed more than 44 people in the Yemeni capital, according to an Agence France Presse tally based on reports by medics, the government and tribesmen.

Tribesmen occupied the state news agency Saba, the building of national airline Yemenia, and tried to storm the interior ministry headquarters, witnesses and a high-ranking Yemen official said.

The latest violence came despite an appeal late on Tuesday by Saleh for supporters of Sheikh Sadiq al-Ahmar, who heads the powerful Hashid tribal federation, to "cease their aggression on security forces."

Saleh, who has warned the situation could deteriorate into civil war, also called on the tribesmen to "withdraw their armed partisans from public buildings and facilities," the defense ministry's 26sep.net news website said, adding security forces would observe a ceasefire.

Gunfire rang out in Sanaa, raising fears among protesters staging a sit-in at University Square, which was dubbed "Change Square" after it became the epicenter of anti-regime demonstrations in February.

Government shelling on Tuesday targeted pro-opposition troops led by dissident General Ali Mohsen al-Ahmar, stationed near the square to protect the demonstrators, his spokesman Askar Zueiyl said.

The rebel forces were "targeted by an artillery shell and several soldiers were killed," Zueiyl told AFP.

A number of residents fled southwards Wednesday to escape the fighting in Sanaa, where there were also electricity and water shortages, an AFP correspondent said.

Those attempting to head north ran into Republican Guards checkpoints and were advised they may not be allowed to return. The area north of the capital is a stronghold of Ahmar's tribe.

Clashes between security forces and Ahmar's followers broke out in the capital on Monday after Saleh refused to sign a deal with the opposition brokered by the Gulf Cooperation Council (GCC) that would see him leave office within 30 days.

The tribesmen occupied public buildings, including the trade and industry ministry, sparking fighting that raged through to Wednesday, barring a brief lull overnight.

General Ahmar, who in March pledged his support to the protest movement that has been calling for Saleh's ouster since late January, has accused the strongman of trying to spark a civil war in an attempt to remain in power.

The Yemeni official, meanwhile, warned the violence will escalate unless the tribesmen vacate the buildings located in or near the al-Hasaba neighborhood where Ahmar lives.

"Sheikh al-Ahmar's men are required to withdraw from the buildings under their control," he said, speaking on condition of anonymity. "Otherwise, we will force them to do so."

A Saba journalist said tribesman had taken over the state news agency's headquarters during the night.

"Armed men stormed the Saba headquarters during the night and demanded that we leave," the journalist told AFP on condition of anonymity.

Access to al-Hasaba, in Sanaa's north, has been cut by cement blocks and burning tires placed in the streets.

Yemen's wealthy Gulf neighbors on Tuesday demanded an immediate halt to the bloody clashes between the regime forces and Ahmar's clansmen.

The regime and Ahmar's tribe have traded accusations about what sparked the deadly clashes.

Sources close to Ahmar said the fighting erupted after security forces tried to deploy around his residence and his gunmen retaliated, while security officials say police intervened when gunmen broke into a nearby school.

One of the 10 sons of Sheikh Abdullah al-Ahmar, who was Saleh's main ally until his death, Ahmar is capable of rallying thousands of armed supporters, tribal sources say.

Yemen has an estimated 60 million firearms in private hands, roughly three for every citizen.

The country's opposition vowed on Monday to step up street protests, while insisting on efforts to avoid violence.