Syrian activists and youth have been staging a sit-in on a section of the key M4 highway that passes through Idlib province to protest what they claim are repeated incursions by Russian forces, a local activist said.

Under the terms of a March 6th ceasefire deal, Russian and Turkish forces have agreed to conduct joint patrols in the area to maintain security on the road.

But some claim Russia has been overstepping the agreement, and has attempted to penetrate deep into this area under cover of the truce, Idlib activist Musab Assaf told Diyaruna.

In an attempt to halt the joint patrols, dozens of demonstrators blocked a section of the strategic highway that passes near the city of Idlib, Assaf said.

The protestors claim Russia is responsible for the death of thousands of Syrian civilians, both directly, by taking part in the military operations, and indirectly with its continued support of the Syrian regime.

The demonstration in turn stirred tensions among armed opposition groups that support the so-called "al-Karama sit-in" and those that oppose it, Assaf said.

"In particular, there has been friction between extremist alliance Tahrir al-Sham and the Syrian Liberation Front, which has led to reciprocal kidnappings and gunfire exchange between the two," he noted.

Tahrir al-Sham captured the military commander of Faylaq al-Sham, Ramadan Dayoub ("Abu Ali Jarjanaz"), and 10 of his comrades following severe tension in the vicinity of eastern rural Idlib's al-Nairab, Assaf said.

Despite the heightened tensions, however, the M4 protestors remain in the area, which is in close proximity to Syrian regime and Russian checkpoints, he said.

Meanwhile, Assaf noted, fighting has erupted between Syrian regime forces and opposition groups in southern rural Idlib, especially in the Kafr Nabl area.

A number of opposition areas, including Safuhen, al-Fatira and al-Bara, came under shelling from regime-allied positions facing those towns, he said.