The agreement, organised by the United States, Russia and Jordan, was broken after forces loyal to Damascus attacked rebel positions.
One rebel brigade reported shooting down a regime military aircraft on Tuesday morning. The New Arab was not able to confirm the claim immediately at the time of publication.
“We shot down a regime military aircraft near Um Remim North West of Mahroutheh in the Syrian desert,” the FSA brigade, Lions of the East Army.
Regime media sources claimed they had only attacked Islamic State (IS), which is considered outside the terms of the agreement, but counter-claims and videos provided by the FSA appeared to disprove the regime’s claims.
Regime media sources said the attack was organised as part of ‘Operation Big Dawn’, a regime offensive to reclaim the Suweida province from the FSA with help from Russian airstrikes.
Regime warplane also dropped a barrel bomb on the town of Daraa in south Syria at 12.10am on Tuesday morning, Free Horan Media, a local media outlet reported.
Suweida and Daraa are inside the ‘de-escalation’ zone applied to the region near the Israel, Jordan border where a ceasefire was supposed to take effect on Sunday at 12pm.
The Russian foreign minister said the ceasefire applied in the areas of Daraa, Quneitra and Suweida, near the Jordanian border.
“At first, security around this de-escalation zone will be guaranteed by the forces and means of the Russian military police, in coordination with the Americans and Jordanians,” said Sergey Lavrov.
Five days of peace talks began in Geneva on Monday, in the latest UN-brokered attempt to bring about a lasting peace in a civil war which has lasted more than six years.
According to independent monitors, hundreds of thousands of civilians have been killed in the war, mostly by the regime and its powerful allies, and millions have been displaced both inside and outside of Syria.
The brutal tactics pursued mainly by the regime, which have included the use of chemical weapons, sieges, mass executions and torture against civilians have led to war crimes investigations.