The French government warned of a "deteriorating situation in Aleppo and northern Syria" on Sunday, as Ankara continued its bombing of Kurd militias and their allies in the area.

Turkey sees the Kurdish YPG units as a direct threat to its safety and is anxious about the group's recent territorial gains near the Turkish border. The country's officials also claim that the shelling is merely a response to incoming fire from the Kurdish positions.

In the Sunday statement, the French foreign ministry urged an "immediate halt to the bombing, both that of the (Syrian) regime and its allies throughout the country and that of Turkey in the Kurdish zones," echoing an earlier US appeal directed at Ankara. The YPG is an important ally of Western countries in the fight against the so-called "Islamic State."

Turkey continuing strikes

The Turkish leadership, however, seemed undeterred in its intent to continue the strikes.

Turkey would not permit the Kurdish units "to carry out aggressive acts," Prime Minister Ahmet Davutoglu said that during a telephone call with German Chancellor Angela Merkel.

"Our security forces gave the necessary response and will continue to do so," he told Merkel, according to his office.

Kurds refuse to leave

The Turkish military used howitzers to target the area around the border town of Azaz and the Menagh airbase, which is controlled by the YPG units. At least three YPG fighters have died since the shelling started on Saturday, Kurdish officials said.

YPG and their allies drove the Islamist rebels out of the Menagh less than a week ago, with the Russian air force backing the Kurdish assault.

The move angered Ankara, which demanded the YPG fighters withdraw immediately. Kurdish officials, however, rejected the demand.

On Sunday, the UK-based Syrian Observatory for Human Rights reported that some 350 Islamist fighters had been allowed to travel through Turkish territory. They were headed to reinforce Syrian rebels fighting the Kurds in Azaz and Tal Rifaat, according to the Observatory.

At the same time, the Syrian regime accused Ankara of sending its own forces across the border and directly supporting the rebels by shelling the YPG.

Ready for ground war

The latest escalation comes as Turkey and Saudi Arabia openly consider sending ground troops to Syria.

Both Ankara and Riyadh are staunch opponents of the Syrian President Bashar al-Assad. The anti-Assad forces are in a dire position, pummeled by Russian warplanes and losing ground to pro-government troops heading towards Aleppo.

The loss of the city would be a devastating defeat for the rebels.

However, Saudi Arabia stated that any move to deploy Saudi special forces across the border would need to be approved by the US-led military coalition for Syria.

On Sunday, Russian Prime Minister Dmitry Medvedev warned that any ground operation in Syria would lead to "a full-fledged, long war."

dj/jm (Reuters, AFP, dpa, AP)