|Defected soldiers of General Ali Mohsen al-Ahmar provide protection for anti-Saleh protesters [EPA]
Fierce clashes have erupted in Yemen's capital between troops loyal to President Ali Abdullah Saleh and forces led by defected General Ali Mohsen al-Ahmar.
Fighting broke out on Thursday in north Sanaa between forces from the elite Republican Guard, led by Saleh's son Ahmed, and soldiers from Ahmar's First Armoured Division, which provides protection for anti-Saleh protesters, witnesses said.
Republican Guard forces based in Amran Street were locked in a heavy exchange of fire with dissident troops deployed in Thalathine Street near Change Square, where protesters demanding Saleh's removal have camped for months, witnesses said.
They said heavy shelling believed to be coming from Republican Guard bases north of the capital was targeting a residential neighbourhood near the state television offices, with residents pleading for help and to be spared.
|For more on Yemen, visit our Spotlight page
Earlier on Thursday, at least one person was killed and five others injured by heavy shelling and gunshots from forces loyal to Saleh in the Sufan neighbourhood of the capital.
In a separate incident, Yemeni security forces opened fire to disperse children at a rally in Ibb, south of Sanaa.
The children were demonstrating against the death of Anas al Saeedi, a 10-month-old baby who was killed in clashes last week.
The protestors want the child's killers, who have yet to be identified, to be put on trial.
Saleh loyalist troops also clashed with Ahmar tribesmen in Al-Hasaba, in renewed fighting with the influential tribe whose leader Sheikh Sadiq al-Ahmar has sided with the protesters.
The gunbattle erupted a day after other tribesmen fighting the Republican Guard north of Sanaa shot down a fighter jet.
The military held opposition leaders responsible for downing the Sukhoi SU-22 near Arhab, 40km north of the capital, a region that is the northern gateway into Sanaa.
In other unrest on Thursday, one civilian was killed and five others were wounded in overnight bombing in Taiz, Yemen's second largest city, which has been the scene of continuing massive anti-Saleh protests.
Saleh, who is under international pressure to relinquish power and allow new elections, returned to the country on Friday, sparking violence in which scores of people have been killed.
The 69-year-old president has repeatedly refused to sign a power transfer deal brokered by the Gulf Co-operation Council under which he would hand over to Vice President Abdrabuh Mansur Hadi in return for immunity from prosecution.
Walid al-Amari, a leading activist from the youth revolution committee, told the AFP news agency that young people are planning to march on Thursday from their encampment at Change Square to the south of the city where Saleh's residence is located.
"There will be an escalation during the coming two days. The youths will march to Hedda Street, where the president's residence is," said Amari.
He said protesters want a peaceful march and have asked the leadership of the defected First Armoured Division not to provide any armed protection that could provoke Saleh loyalists.