BEIRUT (Reuters) - Suicide bombers disguised as farmers struck an army position in western Syria on Tuesday in an attack that killed three people and all the militants, Syrian state-run media said.

The Ansar al-Tawheed group said three of its fighters had carried out the attack on the checkpoint in Taybat al-Imam, north of Hama city. In a statement, it said 30 members of government forces had been killed and wounded.

Violence has escalated of late in the area, the last major part of Syria held by insurgents opposed to President Bashar al-Assad, straining a Russian-Turkish agreement that has staved off a major government offensive.

The Syrian Observatory for Human Rights, which monitors the eight-year-long war, says about 200 civilians have been killed by shelling and bombardment in the region since mid-February, the bulk of them by government attacks on rebel-held areas.

The Observatory said 10 people were killed in Tuesday’s attack in a “demilitarized” zone set up under the Turkish-Russian agreement.

State media said the militants were dressed as local farmers when they hit the position near Taybat al-Imam around 3 a.m. (midnight GMT). A tank supporting them was destroyed.

“The clash between the guards at the position and the terrorists resulted in three martyrs and the killing of all members of the terrorist group,” state media cited a military source as saying.

Ansar al-Tawheed, in its statement, said it would continue “to work against” government forces.

Russia and Turkey struck an agreement last September that staved off a major government offensive into Idlib and adjacent areas of Hama and Aleppo provinces through the creation of the demilitarized zone.

But jihadist groups that hold sway in the Idlib region have further tightened their grip in recent months, and Russia remains keen to help Assad take back the territory.

President Vladimir Putin, Assad’s most powerful ally, discussed Syria with Turkish President Tayyip Erdogan in Moscow on Monday and they agreed to conduct joint patrols in the area, where Turkey has also deployed forces in rebel-held areas.

Last week, Damascus said Russia had started to feel that its patience was running out over the northwest. However, Moscow had told Damascus that Turkey was still determined to implement the agreement.

Idlib and adjoining areas of Hama and Aleppo provinces are largely controlled by jihadist groups including Tahrir al-Sham, formerly known as the Nusra Front.

The United Nations says Idlib and adjacent areas are sheltering some 3 million people, half of them uprooted from other parts of Syria by the war.

Turkish forces control a separate chunk of territory north of Aleppo where Turkish-backed Free Syrian Army rebels are based.