A day after extremist groups missed a deadline under a demilitarisation deal for Syria's Idlib province, Russia said the deal was still going ahead, AFP reported Tuesday (October 16th).

The agreement, reached by Turkey and Russia, gave "radical fighters" until Monday to leave a buffer zone around the last major opposition stronghold.

But they have held their ground, and extremist alliance Tahrir al-Sham pledged to continue fighting -- despite not taking an explicit position on the deal.

By Tuesday, more than 24 hours after the deadline, the Syrian Observatory for Human Rights said there were "no signs" of a Tahrir al-Sham evacuation.

"We did not monitor on Tuesday any withdrawal or patrols in the buffer area," said Observatory head Rami Abdel Rahman.

Russia however said Tuesday the deal was being implemented despite some setbacks.

There was no reaction from Turkey, which observers said was a sign of a de facto grace period to allow the deal to be fully implemented.

Nawar Oliver, an analyst at the Turkey-based Omran Centre, said the deal may still reach fruition, noting that "although the time frame has nominally expired, there are continuing efforts to implement the deal".

Oliver said all stakeholders in the deal, even local actors, realised that the timeframe granted in the public agreement would not be enough.

"That is why it needs more time," he said.

One possible hurdle is the internal divide within Tahrir al-Sham over the deal.

According to a brief this month by the Omran Centre, Tahrir al-Sham chief Abu Mohammad al-Joulani appears supportive of the deal and of aligning with the National Liberation Front, the second-most-powerful group in Idlib.

A second faction, led by an Egyptian commander, was leaning towards rejecting the deal and any partnership with the National Liberation Front.