Hundreds of women took the streets on Saturday to call for the end of Saleh's rule [AFP]

At least four Yemeni soldiers have been killed in clashes with armed opposition tribesmen in the city of Taez, 200km south of Sanaa, the country's capital, tribal sources and witnesses said.

The clashes broke out on Saturday as security forces allegedly tried to attack a central square where tens of thousands of anti-government protesters have camped out for over five months, medics said.

Four troops of the elite Republican Guards and four tribesmen, who consider themselves 'defenders of the revolution', were also reportedly wounded in the fighting. 

Taez, the country's second largest city, has been a flashpoint of nationwide protests calling for the end of the rule of Ali Abudullah Saleh, who has been in power since 1978.

Dissident armed tribesmen were deployed to help protect the city's protesters following a reported massacre by government troops there.

The UN human rights office said that more than 50 people were killed in the city in a crackdown on protesters over several days in late May.

Then in early June, a top tribal chief said that armed dissidents had seized control of most of Taez, following clashes with troops loyal to Saleh.

"I consider Taez to have fallen under the control" of the dissidents, Sheikh Hammoud Saeed al-Mikhlafi, the head of the tribal council in Taez, told the AFP news agency.

Meanwhile, Yemen's official Saba news agency reported on Saturday that 79 people have been referred to court for alleged involvement in the March 18 massacre of 52 people in Sanaa near the site of an anti-regime sit in.

"The prosecutor general today (Saturday) referred 79 accused to court for killing and wounding a number of citizens in the university area of the capital on March 18, 2011," Saba cited a source in the prosecutor's office as saying.

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It did not elaborate on the identities of the suspects or the charges against them.

Witnesses said that on March 18, pro-Saleh "thugs" had sprayed bullets from rooftops around a square at Sanaa University, a centre of anti-government demonstrations.

Many of the victims were shot in the head and more than 120 people were wounded, medics said, in scenes that drew widespread condemnation from Western powers and human rights groups.

Soldiers missing

Also on Saturday, a Yemeni commander said that 50 soldiers were missing in south Yemen after clashes with suspected al-Qaeda linked fighters.

"We have lost all trace of 50 soldiers after an attack by Al-Qaeda elements enabled them to recapture control of the Al-Wahda stadium" outside Zinjibar, the provincial capital of Abyan, the commander told the AFP news agency on condition of anonymity.

He did not know if the troops had been killed, captured or had deserted in the battle for the stadium which the army recaptured from the fighters on Friday.

The commander accused the defence ministry of abandoning the brigade's soldiers to their fate in the face of repeated attacks by fighters of the Partisans of Sharia (Islamic Law) movement who seized much of Zinjibar in late May.

The Sanaa government says the fighters in Zinjibar are allied with al-Qaeda, but the opposition accuses it of playing up the threat in an attempt to gain international support to keep Saleh in power.