BEIRUT — Syrian rebels have launched an offensive to "liberate" the country's largest city of Aleppo, an opposition commander said Sunday, while in Damascus government troops backed by helicopter gunships wrested back control of rebel-held neighborhoods.
The opposition attack on Aleppo, Syria's commercial hub and traditionally a bedrock of support for President Bashar Assad, was a sign of the rebels' growing confidence and capabilities even as regime forces appeared close to regaining control of the capital Damascus after days of bloody street battles.
With Syria's civil war moving from the countryside and smaller cities into the country's two main urban centers, an activist group said the death toll had risen to more than 19,000 since the uprising began in March 2011. The Syrian Observatory for Human Rights also said July is shaping up to be the deadliest month of the conflict so far, with 2,752 people killed in the first three weeks — already nearly as many as the previous month.
The bloodshed has escalated as the rebels have taken the battle to the government with a week of fighting in Damascus, including a bombing that struck at the core of Assad's regime, killing four senior officials.
"Right now Assad's inner circle has been dismantled and Assad has lost his balance," said Brig. Gen. Abdul Kareem al-Ahmad of the Free Syrian Army at a meeting in Turkey. "This war is now being waged in the heart of Syria in Damascus."
In a bid to seize the momentum, the opposition also has taken control of several border crossings with Iraq and Turkey.
A video posted online by activists Sunday showed about a dozen gunmen standing in front of the Bab al-Salamah crossing on the Turkish frontier as they raised the Syrian opposition flag.
Yet, even as the rebels seized one crossing, they abandoned another. Iraqi military officials and state television reported that Syrian government forces retook control of the remote desert Rabiya crossing after rebels pulled out. South of Rabiya, the rumble of fighting could be heard from the larger Bukamal crossing near the Iraqi town of al-Qaim.
Brig. Gen. Manaa Rahal of the Free Syrian Army confirmed there were three border crossings in rebel hands — two along the Turkish frontier and the Bab al-Yarubiyeh in the far north in Iraq's Kurdish region.
"The seizure of these border crossings was a crucial victory for the opposition and its strategic importance will only increase," he said in the meeting in Turkey's Hatay province.
Damascus and Aleppo are both home to elites who have benefited from close ties to Assad's regime, as well as merchant classes and minority groups who worry their status will suffer if Assad falls.
Col. Abdul-Jabbar Mohammed Aqidi, the commander of rebel forces in Aleppo province, said in the video posted on Youtube, "we gave the orders for the march into Aleppo with the aim of liberating it."
He called on government troops to defect and join the opposition, and said rebels will protect members of President Bashar Assad's Alawite minority sect, an off-shoot of Shiite Islam, saying "our war is not with you but with the Assad family."
The Britain-based Syrian Observatory for Human Rights and Aleppo-based activist Mohammed Saeed said the fighting is concentrated in several neighborhoods.
Saeed said rebels are in full control of the central Salaheddine district and the nearby Sakhour area. He added that thousands of residents have fled tense quarters of the city for safer neighborhoods and the suburbs.
"Aleppo is witnessing serious street battles," Saeed said, with fierce clashes on the road leading to the city's international airport, known as Nairab, as rebels tried to surround the airfield to prevent the regime from sending reinforcements.
Syrian state TV, however, played down the scale of the violence, saying government troops were hunting down "terrorists" and killing large numbers of them. The government refers to those trying to overthrow Assad's regime as "terrorists."
In the capital of Damascus, the Observatory also reported attacks by government forces in the neighborhoods of Mazzeh and Barzeh that had once been held by rebels. It said that troops used helicopters gunships in the attack, causing heavy casualties.
Maj. Gen. Nabil Zughaib, described as a missile expert, was also shot dead along with his wife and a son in the Damascus neighborhood of Bab Touma, according to the Observatory.
Syrian state TV denied government forces were using helicopters in Damascus, and said the capital was calm and troops were just mopping up the remnants of the "terrorists" in cooperation with residents.
Television also showed images of calm streets in Damascus and workmen cleaning up rubble in the once-rebel held Midan neighborhood, in effort to portray a capital where everything has returned to normal.
Assad, meanwhile, appeared on state TV receiving Gen. Ali Ayyoub, the new army chief of staff, whose predecessor replaced the defense minister slain in the bombing. It was only Assad's second appearance since the attack.
Despite the regime's efforts to present an image of calm in the capital, Malaysia's government said it was shuttering its embassy in Damascus and evacuating more than 130 students and diplomats, while Italy ordered of its citizens to leave the country because of the "progressive deterioration" of the situation.
The escalating bloodshed and increasing chaos also has put Syria's neighbors on edge, particularly Israel.
Prime Minister Benjamin Netanyahu said Sunday that Israel was closely monitoring the violence in Syria for signs the regime's chemical weapons or missiles might make their way into the hands of anti-Israeli militants.
Over the weekend, Israel's defense minister, Ehud Barak, said the Jewish state was preparing for a possible attack to prevent that from happening.
For his part, King Abdullah of Saudi Arabia has announced the start of a "national campaign to collect donations to support our brothers in Syria," suggesting the oil-rich kingdom may be looking to boost its financial support for the rebels, which they are already believed to be funding.
Associated Press writers Suzan Fraser in Ankara, Turkey, and Sameer A. Yacoub in Baghdad contributed to this report.