BEIRUT (Reuters) - A suspected Islamic State suicide attack on the governing council of insurgent-held Idlib in northwest Syria on Tuesday killed one person and injured three others, the Syrian Observatory for Human Rights said.

The target was the National Salvation Government in Idlib city, which is linked to the jihadist Tahrir al-Sham alliance that controls much of the enclave in northwestern Syria.

The attack, which the Observatory said was carried out by a woman, follows a succession of blasts in the rebel-held northwest in recent months, where rival factions have fought for control.

Tahrir al-Sham, formed by merging several groups led by al Qaeda’s former Syrian affiliate the Nusra Front, gained control over most of Idlib this month after fighting insurgent factions supported by Turkey.

Its gains there have raised questions over the fate of a deal agreed last year between Damascus’ ally Russia and the rebels’ ally Turkey to maintain peace in northwest Syria. A Kremlin spokesman was quoted this week saying the deal had not been fully implemented.

Islamic State has lost almost all its remaining territory in Syria, but has maintained a guerrilla presence, claiming a series of bomb attacks in northeast Syria, an area held by a Kurdish-led militia backed by U.S. forces.

Other recent bombings have taken place in areas controlled by both Turkey-aligned rebels in the north and in cities under government control, but without any group claiming the attacks.