Syrian rebel fighters fought to control a key road to the Turkish border and turned captured tanks against a government air base north of Syria's largest city on Monday.
The tanks came from the rebel seizure of an army outpost outside Aleppo, the scene of heavy fighting for more than a week. Rebel troops overran the outpost early Monday and were hauling out tank shells and crates of ammunition by afternoon.
The outpost was a restaurant outside the town of Anadan, about 10 kilometers (6 miles) north of Aleppo, that had been commandeered by government troops and surrounded by earthworks. Rebels were putting the captured armor to work Monday by shelling an air base outside Azaz, about 40 kilometers (25 miles) farther north, said Ahmed Afesh, a commander with the rebel Free Syrian Army.
Afesh showed off two Soviet-era T-55 tanks captured by his men Monday, as well as an armored personnel carrier and the smoldering wreckage of another destroyed during the fighting. Rebel fighters and civilians greeted him with handshakes and kisses.
The rebels also have been able to establish growing enclaves in northern Syria and made attempts to seize a number of key border crossings last week. They already control much of the main western highway from Aleppo, Syria's commercial capital and largest city, to the Turkish border. And after the overnight battle outside the town of Anadan, traffic moved freely on a road that had been too dangerous for motorists days before.
But fighting continued inside Aleppo on Monday. U.N. observers reported the use of helicopters, tanks and artillery in the city, the head of the international monitoring mission, Lt. Gen. Babacar Gaye, said Monday. And opposition activists said government forces used helicopter gunships to launch rocket attacks on rebel fighters.
At least 85 people were killed across Syria on Monday, including 25 in Aleppo, according to the opposition Local Coordination Committees of Syria.
There were conflicting reports on who controlled the major Aleppo neighborhood of Salahuddin, which rebels had claimed days earlier. Both opposition fighters and the regime said they had taken over Salahuddin, where Al Jazeera correspondent Omar Khashram was wounded during heavy fighting Monday.
A cameraman and driver working with Khashram, who was being treated in a hospital in Turkey, told CNN that shrapnel from a shell penetrated gaps in the correspondent's flak jacket.
About 200,000 people in and around the city have fled shelling and heavy weapons fire in the past two days, Valerie Amos, the U.N. undersecretary-general for humanitarian affairs, said Sunday.
In several neighborhoods, those who remained were left without phone, Internet or electricity service as tanks shelled the city, according to Deama, an activist in the city. CNN isn't using her full name because disclosing it could put her in danger.
"We're afraid they are going to do something worse. Usually, they will cut off connections and isolate these neighborhoods more when they are about to make something worse," Deama said Monday.
Residents also faced bread and flour shortages, she said. Bakeries were shuttered.
"This is like punishment from the regime. They want to make people hungry," she said.
Protests against Syrian President Bashar al-Assad, whose family has ruled the country for more than 40 years, began in March 2011. Security forces launched a violent crackdown on peaceful protests that has been met by increasingly stiff resistance, with large numbers of government troops joining the opposition.
The conflict has now claimed nearly 17,000 lives, U.N. Secretary-General Ban Ki-moon said last week, while opposition activists put the toll at more than 20,000.
In Iran, one of Syria's few remaining allies, Foreign Minister Walid Moallem vowed Monday that the rebels would not take Aleppo.
"Since last week, (opposition fighters) planned for whatever they called the 'great Damascus battle,' but they have failed after one week," Moallem said, referring to a rebel offensive beaten back earlier this month. "That's why they moved to Aleppo, and I can assure you that they will fail."
In Turkey, where more than 43,000 Syrians have taken refuge since the crisis began, two convoys of Turkish troops, including tanks, were seen moving into the border town of Kilis. A high-ranking police official from the Syrian city of Latakia defected to Turkey on Monday, as well as 11 other Syrian officers, the Turkish Foreign Ministry said.
In Paris, French Foreign Minister Laurent Fabius said his country will take more action to try to stop the bloodshed when it assumes the rotating presidency of the U.N. Security Council on Wednesday.
"We are going to ask -- before the end of the week -- for a meeting of the Security Council, probably at a ministerial level ... to try and stop the massacres and prepare for the political transition," Fabius told French RTL radio on Monday.
In London, the top diplomat at the Syrian Embassy resigned his post, the British Foreign & Commonwealth Office said. Charge d'Affaires Khaled al-Ayoubi told British officials that he was "no longer willing to represent a regime that has committed such violent and oppressive acts against its own people," the office said in a statement.
In Washington, the White House said President Barack Obama and Turkish Prime Minister Recep Tayyip Erdogan "shared their growing concerns about the Syrian regime's ruthless attacks against its own people, most recently in Aleppo, and the deteriorating humanitarian conditions throughout Syria as a result of the regime's atrocities" in a telephone call Monday.
"The two pledged to coordinate efforts to assist the growing numbers of displaced Syrians, not only within Syria, but in Turkey and the broader region. The president acknowledged the generosity of the Turkish people in hosting so many Syrians who have fled their homes in search of safety in Turkey."
And in Tunisia, his first stop on a visit to the Middle East, U.S. Defense Secretary Leon Panetta told CNN that al-Assad "knows he's in trouble, and it's just matter of time before he has to go."