Battle rages for Syria's Aleppo airport

Hundreds of troops backed by military vehicles poured into the northern province of Aleppo on Tuesday following rebel advances and as a battle raged for control of Syria's second-largest airport, a watchdog said.
The reinforcements arrived at the town of Tal-Aran in the southeast of the province, the Syrian Observatory for Human Rights said.
The deployment follows unexpected advances by the rebels in their thrust to seize control of air bases in northern Syria and to capture Aleppo's international airport.
"A large number of troops are currently approaching Aleppo from the east, redeployed from central Syria, to keep the rebels from taking the country's second-biggest airport," said Observatory director Rami Abdel Rahman,
"The army will not let Aleppo international airport go without a big fight."
In the past week, rebels have captured air bases at Al-Jarrah, Hassel and Base 80, as well as an important checkpoint near the international airport.
On Monday, they made a brief incursion into the airport's fuel warehouse before the army pushed them out, a military source said.
The source also said the rebels had seized a building strategically located 200 metres (yards) from the airport.
Fighting between rebels and troops also erupted Tuesday in southern Damascus, where the army deployed reinforcements in a bid to drive insurgents out of belts surrounding the capital, the Observatory said.
"Rebels and regular troops clashed at the entrance to Yarmuk (Palestinian) refugee camp in Damascus," said the watchdog.
Pro-regime daily Al-Watan at the same time reported "clashes near Sayyida Zeinab (southeast of Damascus) and the surroundings of Yarmuk camp".
The camp housing thousands of Palestinian refugees has seen fierce fighting inside and outside its premises since late last year.
Throughout much of the winter, the army has been engaged in a bid to keep approaching rebels out of Damascus, making daily attacks on their enclaves all around the capital.
But in Damascus province, as in much of the rest of the country, rebels and the army have reached a military stalemate, said Abdel Rahman.
"Across Syria today, there are hundreds of flashpoints. Both the army and the rebels are overstretched," he said.
"While the rebels have made significant advances in some areas such as Aleppo province, the army is not going to let any strategic area slide. So what we are looking at is a long-term war of attrition."
The United Nations says that nearly 70,000 people have been killed in the Syrian conflict.
On Monday at least 154 people were killed in violence across Syria, among them 63 soldiers and 54 rebel fighters, said the Observatory.