BEIRUT       
 (AP) -- Turkey shelled positions held by a U.S.-backed Kurdish militia 
in northern Syria for a second day on Sunday, drawing condemnation from 
the Syrian government, whose forces are advancing against insurgents in 
the same area under the cover of Russian airstrikes.
Turkey's
 state-run Anadolu Agency said Turkish artillery units fired at Kurdish 
fighters in the Syrian town of Azaz in Aleppo province, saying it was in
 response to incoming Kurdish fire.
Turkish 
troops have shelled areas under the control of Syria's main Kurdish 
faction, the People's Protection Units, known as YPG, in the past. The 
group has been most effective in the fight against the Islamic State 
group in Syria, but Ankara appears increasingly uneasy over the group's 
recent gains in the country's north.
"Turkey 
has responded in this manner in the past," said Turkey's Deputy Prime 
Minister Yalcin Akdogan. "What is different is not that Turkey has 
responded in such a way but the fact that there are different movements 
in the region. The YPG crossing west of the Euphrates is Turkey's red 
line."
The YPG is the main fighting force of 
Syrian Kurds and a key ally of the U.S.-led coalition battling the 
Islamic State group. Turkey, which is also in the alliance, considers it
 an affiliate of the Kurdistan Workers' Party, or PKK, which has waged a
 decades-long insurgency against Ankara.
A 
coalition of Kurdish-led Syrian fighters known as the Syrian Democratic 
Forces recently seized a number of villages near Turkey's border. Ankara
 appears concerned they could reach the opposition stronghold of Azaz, 
which is home to a major border crossing that has been controlled by 
militants since 2012.
Diplomats from a group 
of countries that have interests in Syria's five-year civil war, 
including the U.S., Russia, Turkey, Saudi Arabia and Iran, agreed on 
Friday to seek a temporary "cessation of hostilities" within a week. But
 the fighting on the ground, which has sent tens of thousands of people 
fleeing toward the Turkish border where they continue to sleep in the 
open air, has accelerated.
A top Syrian 
opposition figure, former Prime Minister Riad Hijab, criticized Russia 
on Sunday for continuing with its bombing in Syria, and also stopped 
short of declaring a clear commitment to implement a planned temporary 
truce.
"You ask me if I accept a cease-fire or
 a cessation of hostilities. I ask you: Why is the onus on the 
opposition and whether it has preconditions for negotiations?" Hijab 
said. "I would like to see a single day of a cessation of hostilities in
 order to give a chance for real political movement." He was addressing 
the Munich Security Conference, an annual gathering of foreign and 
security policy leaders.
Akdogan says Kurdish 
gains in northern Syria - facilitated by a Russian-backed government 
offensive in the same area - are also putting "unacceptable" pressure on
 opposition-held areas in Aleppo and the nearby town of Tel Rifaat.
The
 private Dogan news agency broadcast footage of Turkish howitzers 
opening fire and shells raising plumes of smoke in Syria. It said the 
army hit targets in the Mannagh air base and two villages, all 
controlled by Syrian Kurdish fighters.
The 
Syrian Observatory for Human Rights, an opposition group that monitors 
the conflict, said two fighters from the SDF - a coalition of Kurdish 
and Arab fighters - have been killed and seven others wounded in the 
shelling. A Turkmen rebel commander, Zakariyya Karsli, told Anadolu 
Agency Turkish shelling killed at least 29 Kurdish fighters.
Opposition
 groups said Saturday that Turkish troops fired artillery shells that 
targeted the Mannagh air base in Aleppo province, which was captured by 
Kurdish fighters and their allies earlier this week.
Turkish
 Prime Minister Ahmet Davutoglu said late Saturday that his country's 
military fired at Kurdish fighters in northern Syria in response to a 
provocation along the border.
The Syrian 
government condemned Turkey's shelling of Syrian territory, describing 
it as an attempt to raise the morale of "terrorist" groups it supports.
France
 meanwhile called on Syria and Russia to halt their airstrikes and for 
Turkey to stop shelling Kurdish areas. In a statement, it expressed 
concern about the "deteriorating situation in Aleppo and northern 
Syria."
Both the Kurds and Syrian troops have 
advanced toward Azaz in separate offensives in the area. In addition to 
sealing the Turkish border, Syrian troops are trying to encircle 
rebel-held parts of Aleppo, Syria's largest city. If they are able to do
 so, it will be the biggest defeat for insurgents since the conflict 
began in March 2011.
The Observatory and the 
Lebanon-based A-Mayadeen TV said at least 350 Turkey-backed armed rebels
 crossed into Syria from Turkey Sunday to shore up rebels fighting Kurds
 near Tel Rifaat.
Also on Sunday, Iran's air 
defense chief said his country is ready to help defend Syria's airspace,
 marking the first time Iran has offered to assist with Syrian air 
defenses.
The semi-official Tasnim news agency
 quoted Gen. Farzad Esmaili as saying "we will help Syria in a 
full-fledged manner if the Syrian government requests help." He said any
 such aid would be provided in an "advisory" capacity.
Iran
 is a close ally of Syrian President Bashar Assad and has sent weapons, 
money and military advisers to Syria to help bolster his forces.
Esmaili's
 remarks came after Turkey and Saudi Arabia -- leading supporters of the
 rebels battling to topple Assad -- said they were open to sending 
ground troops into Syria to battle the Islamic State group. Turkey's 
foreign minister, Mevlut Cavusoglu, also said Saturday that Saudi Arabia
 is "ready to send both jets and troops" to Turkey's Incirlik air base.
Fighting
 and airstrikes continued elsewhere in the country Sunday, including in 
rebel-held suburbs of the capital Damascus. Opposition activists 
reported Syrian army helicopters dropped around 10 barrel bombs on the 
town of Daraya. There was no immediate word on casualties.
 
 
 
 
 
 
 
 
 
 
 
 
