Syrian tanks have shelled the rebel-held Damascus suburb of al-Mouadamiya, killing several people, activists say, a day after the UN wound up its troubled observer mission to the country.
Haya, an activist in Mouadamiya, said the offensive began on Monday at 6am local time (03:00 GMT).
"Tanks were dispatched from al-Mezze airport base and Brigade 555 from Somarieh and have now almost surrounded Mouadamiya," she said by telephone, referring to nearby military bases.
The rebels had repelled at least one attempt by a tank unit to enter the southwestern suburb, Haya said.
Clashes also raged in Aleppo on Monday, as rebels resisted a regime onslaught launched in the northern city a month ago.
Troops backed by helicopters pounded several districts, including parts of Salaheddin neighbourhood where much of the regime's military operations against the rebels have been focused.
In the country's south, Syrian activists said clashes between rebels and regime forces killed six people, including two children and two women, in the city of Daraa, birthplace of the country's 18-month-old uprising.
Besides the fighting, Syrians have had to face food shortages, the closure of many shops, and street demonstrations at Eid, the festival celebrated by Muslims across the world to mark the end of the holy month of Ramadan.
'Rockets fell in Jordan'
Syrian President Bashar al-Assad made a rare public appearance on Sunday with top officials for Eid prayers at a Damascus mosque, while demonstrators took to the streets of the Syrian capital and other cities to vent their rage at his regime.
"Eid is here, Eid is here, God curse you, O Bashar," protesters in Qudsaya in Damascus province sang to the tune of Jingle Bells, according to amateur video posted on YouTube.
In neighbouring Jordan, authorities in Amman said four rockets fired from Syria fell inside its northern border area, wounding a four-year-old girl.
In-depth coverage of escalating violence across Syria
"We are in touch with the Syrian sides to determine what happened," Samih Maaytah, information minister and government spokesman, told AFP news agency on Monday.
"The Jordanian government summoned the Syrian ambassador in Amman and gave him a letter of protest. Jordan rejects what happened and will make sure it does not occur in the future."
Jordan currently hosts more than 150,000 Syrian refugees. Many of them come under Syrian army fire as they flee to the kingdom, whose troops provide covering fire.
Turkey, meanwhile, hosts nearly 70,000 refugees from Syria and, on Monday, the Turkish foreign minister told a local paper that his country may soon run out space to house more people fleeing violence in Syria.
"If the number of refugees in Turkey surpasses 100,000, we will run out of space to accommodate them. We should be able to accommodate them in Syria," Ahmet Davutoglu was quoted as telling the Hurriyet newspaper.
"The United Nations may build camps in a safe zone within Syria's borders."
UN mission ends
The latest development came as UN observers ended their troubled mission in Syria at midnight on Sunday in the face of the escalating violence and a failure by world powers to agree on how to tackle Assad and bring about peace to the country.
Al Jazeera's Stefanie Dekker reports on sombre Eid celebrations in Turkey refugee camps
Created after a UN Security Council resolution in April, a team of some 300 truce monitors was progressively deployed into Syria as part of UN-Arab League envoy Kofi Annan's six-point plan to end the conflict.
Much of its operations in the field were suspended in June and its numbers cut back in the face of the mounting violence, as both sides violated a ceasefire that was meant to have been the cornerstone of Annan's plan.
The end of the mission came just days after the veteran Algerian diplomat Lakhdar Brahimi was named to replace Annan.
"A civil war, it is the cruellest kind of conflict, when a neighbour kills his neighbour and sometimes his brother, it is the worst of conflicts," Brahimi said in an interview with France 24 television in Paris on Monday.
"There are a lot of people who say that we must avoid civil war in Syria, me I believe that we are already there for some time now. What's necessary is to stop the civil war and that is not going to be easy."