Syria regime shells rebel-held region in southwest

Any major battle near border with the Israeli-occupied Golan Heights might risk a serious escalation in Syria's war.

DAMASCUS - The Syrian army and its allies bombarded rebels in the southwestern Daraa region on Friday, killing at least six people, a war monitor said, in a region widely seen as a potential flashpoint for further escalation in the conflict.

The Syrian Observatory for Human Rights reported that the army had shelled the towns of Kafr Shams and al-Harah, near the border with the Israeli-occupied Golan Heights region.

It was the highest death toll from bombing since a "de-escalation zone" was agreed in southwest Syria last year by the government's ally Russia, along with Jordan and the United States. 

Negotiations are continuing in a bid to reach a deal for the province that would remove the need for a government offensive.

Any major battle in the area might risk a serious escalation in Syria's seven-year war, pitting Israel more directly against Iran and its allies.

President Bashar al-Assad has sworn to take back every inch of Syria and has been preparing an assault on rebels holding areas in the southwest bordering Israel and Jordan.

His military gains in the war have partly depended on support from Iran and allied Shi'ite militias including Lebanon's Hezbollah, which have provided ground forces.

Israel wants those forces removed from all of Syria, but is particularly sensitive to their presence near its frontier, and has carried out numerous air strikes against them. It regards Iran as its biggest external threat, and Hezbollah as the biggest threat on its borders.

The United States has also warned the government it would take "firm and appropriate measures" in response to any violations of the southwest de-escalation zone.

"We reiterate that any Syrian government military actions against the southwest de-escalation zone risk broadening the conflict," US State Department spokeswoman Heather Nauert said in a statement.

Also at stake in the current talks are the future of a US military base in southeastern Syria.

Assad said in an interview earlier this week that contacts were ongoing between Russia, the US and Israel over the southern front.

"We are giving the political talks a chance, but if they fail, there will be no choice but liberation by force," he said. So far rebel groups, who still control about two thirds of Daraa, have refused to negotiate with the Syrian regime.

The regime wants rebels to withdraw from the area either by force or under a deal similar to those that saw armed groups transferred from their bastions in and around Damascus.

A commander in the military coalition backing Assad also said this week that the preparations for an offensive in the area were complete, and that the government had installed new anti-aircraft defences near the Golan Heights frontier.