Rebels in Syria staged a surprise dawn attack on Sunday against the key district of Baba Amr in the central city of Homs, a year after regime forces retook it after a deadly month-long siege.
The attack came as Islamist insurgents in the oil-producing east of the war-ravaged country said they had established local religious committees to administer the area, including policing, the judiciary and emergency services.
The assault on a key hub of the uprising against President Bashar al-Assad's regime also comes two years after the outbreak of peaceful protest against his rule descended into armed conflict when the regime responded with a brutal crackdown.
"At dawn, the rebels launched a surprise attack on Baba Amr, which they have entered," Syrian Observatory for Human Rights director Rami Abdel Rahman, who was in contact with the rebels, told AFP.
For more than a month in 2012, regime forces pounded Baba Amr relentlessly, seeking to oust insurgents holed up in Homs. Assad's troops eventually retook the district on March 1 last year after a bloody campaign.
Assad himself toured the battered neighbourhood last March 27, assuring residents who had stayed that it would be rebuilt and that normal life would resume in Baba Amr.
Hundreds of people, many of them civilians, were killed in the fighting that left much of the neighbourhood in ruins, according to rights groups.
As well as those killed in Baba Amr, dozens of bodies were found in neighbouring districts of Homs, and included those of people fleeing the fighting, according to the Observatory.
Two foreign journalists, American reporter Marie Colvin of The Sunday Times in Britain and French photojournalist Remi Ochlik, were among those killed when a makeshift media centre in Baba Amr was shelled by Syrian forces.
In the east of the country, where large swathes of territory are now under rebel control, rebel groups including the jihadist Al-Nusra Front have set up a religious council to administer affairs, the Observatory said on Sunday.
"God commanded the Islamic battalions to form a religious council in the east to administer the affairs of the people and fill a security gap," the groups said in a statement distributed by the Britain-based watchdog.
The council will include several offices charged with functions including justice, policing and emergency services, it said.
Video footage showed an convoy draped with black flags bearing Islamic inscriptions in the Deir Ezzor area and rebels attaching a banner to a building in Mayadeen, on which is written "Religious Committee of the Eastern Region."
Rebels in the eastern provinces of Deir Ezzor, Hassaka and Raqa have made significant military gains as they battle Assad's forces.
The Al-Nusra Front, completely unknown before the rebellion, has been a rebel standard-bearer since mid-2012 when it became the spearhead of the insurgency ahead of the Free Syrian Army.
FSA fighters, composed mainly of army deserters, have told AFP that despite being fewer in number, the Al-Nusra jihadists have better logistic and economic backing and receive financing "from abroad."
The Front has focused on strategic targets in the east such as oil wells, and also recruits and pays local fighters. It makes no secret of its aims to see Syria become an Islamist state.
Damascus accuses both Saudi Arabia and Qatar of financing Islamist groups battling the regime.
It labels all armed opposition "terrorists" financed from abroad in the insurgency which the United Nations says has killed more than 70,000 people since it erupted in March 2011.
Meanwhile in Manila on Sunday, the government hailed Saturday's release of 21 Filipino UN peacekeepers freed by Syrian rebels into Jordan after they were abducted on the Golan on Wednesday.
President Benigno Aquino "was very happy to receive the news," his spokeswoman said.