Syrian troops on Friday attacked a convoy trying to evacuate the wounded from a central town near the border with Lebanon, killing at least seven people, as rebel reinforcements infiltrated the besieged area to fight government forces backed by Lebanese Hezbollah fighters, activists said.
The battle for the town of Qusair has exposed Hezbollah's growing role in the Syrian conflict, which has killed more than 70,000 over the past two years.
The Shiite militant group, fighting in Syria alongside President Bashar Assad's troops, initially tried to play down its involvement but abandoned the attempt after dozens of its fighters were killed in the Qusair area and buried in large funerals in Lebanon.
The Britain-based Syrian Observatory for Human Rights said Friday's attack in Qusair also wounded "tens of people." Qusair-based activist Hadi Abdullah described the attack to The Associated Press via Skype, saying it killed nine and wounded about 80.
Abdullah said he was with the convoy evacuating scores of wounded, when troops started firing shells and machine guns. "Women and children jumped out of the cars and started running in fear," Abdullah said.
About 800 wounded remained behind in the town's rebel-held areas, said Abdullah, adding that the main makeshift hospital in Qusair and a home that had been turned into a clinic were hit.
Along with Hezbollah, Russia has also remained a staunch Assad ally in the conflict. On Friday, Russia's MiG aircraft maker announced plans to sign a new agreement to ship at least 10 fighter jets to Syria, a move that comes amid international criticism of earlier Russian weapons deals with Assad's regime.
MiG's director general, Sergei Korotkov, said a Syrian delegation was in Moscow to discuss a new contract for MiG-29 M/M2 fighters. Russian news agencies cited him as saying Syria wants to buy "more than 10" such fighters, but wouldn't give the exact number.
Hours after the Russian announcement, the U.S. and Germany lashed out at Moscow's intentions to provide the Assad regime with an advanced air defense system, which they believe could prolong Syria's civil war.
Secretary of State John Kerry said Russia's transfer of the S-300 missiles would not be "helpful" as the U.S. and Russia jointly try to get the Syrian government and opposition into peace negotiations. The peace talks were initially planned for Geneva next month but have been delayed until July at the earliest.
After meeting Kerry, German Foreign Minister Guido Westerwelle said Russia must not "endanger" the peace talks, describing weapon deliveries to Assad as "totally wrong."
Meanwhile, the Syrian National Coalition, the country's main opposition group, increased the number of members in its general assembly, adding 51 new secular and rebel representatives. A statement by the SNC said the body now has 114 members.
In Damascus, state-run Syrian TV said troops captured later Friday the village of Jawadiyeh outside Qusair, closing all entrances leading to the town and tightening the government's siege.
The regime and the opposition both value Qusair, which lies along a land corridor linking two Assad's strongholds, Damascus and the heartland of his minority Alawite sect, an area along the Mediterranean coast. For the rebels, holding the town means protecting their supply line to Lebanon, just 10 kilometers (six miles) away.
Over the past weeks, government troops and Hezbollah fighters captured wide areas around Qusair and earlier this month launched an offensive on the town, which has been in rebel hands for over a year. Dozens of troops, Hezbollah fighters and rebels have been killed in the latest battles.
Last week, Hezbollah leader Sheik Hassan Nasrallah firmly linked the militant group's fate to the survival of the Assad regime, raising the stakes not just in Syria, but also in Hezbollah's tense relations with rival groups in Lebanon.
Rebels have resisted the government push into Qusair, and days ago called on forces around the country to move to join the fight for the town.
The Observatory and Abdullah said that organized groups of rebels from the northern province of Aleppo managed on Friday to enter areas of the town still in rebel hands to help defend it.
"Individuals have come in the past, but this is the first time that groups of rebels have arrived here," Abdullah said.
Assad's troops have also launched a new offensive in the northern province of Aleppo in an attempt to lift a siege imposed by rebels on the towns of Nobol and Zahraa that are predominantly Shiite and loyal to the government, the Observatory said. It added that rebels are bringing reinforcements to the area.
In the past, Russia has said that it's only providing Assad with weapons intended to protect Syria from a foreign invasion, such as air defense missile systems. It has claimed it is not delivering weapons that could be used in Syria's two-year civil war.
But the delivery of MiGs would contradict that claim and expose Russia to global criticism, possibly forcing the Kremlin to think twice before giving the go-ahead.
There was also the possibility that Korotkov, the MiG chief, was referring to a deal the company previously negotiated with Syria that was apparently put on hold amid the civil war.
Russian media have said that Syria placed an order a few years ago for 12 MiG-29 M/M2 fighters - an advanced version of the MiG-29 twin-engine fighter jet, which has been a mainstay of the Soviet and Russian air force since mid-1980s - with an option of buying another 12. The Stockholm Peace Research Institute also has reported that Russia planned to provide Syria with 24 of the aircraft.
Moscow has shipped billions of dollars' worth of missiles, combat jets, tanks, artillery and other military gear to Syria over more than four decades.
Damascus is now Russia's last remaining ally in the Middle East and along Syria's coast, hosts the only naval base Moscow has outside the former Soviet Union.
Russia has shielded Assad from U.N. sanctions and has continued to provide his regime with weapons despite the uprising against him that began in March 2011.