Fighters affiliated with Libya’s Government of National Accord (GNA) say they seized a building Sunday used by the Takfiri Daesh terrorists for making explosives in the militants’ stronghold of Sirte.

Forces loyal to the GNA shared images of the building on Facebook showing rooms containing explosive devices, mobile phones and cables.

The building, which can be referred to as a bomb factory and is located in the southeast of Sirte, is the largest structure to have been captured in recent months by the fighters.

The GNA has been working to unite factions in Libya since it was established in the capital Tripoli in March.

Figures show that at least 280 Libyan troops have been killed and more than 1,500 wounded since May, when the country's forces began an offensive to liberate Sirte from Daesh. The city is located about 450 kilometers (280 miles) east of Tripoli.

In recent weeks, forces loyal to the GNA have been preparing for a final assault to retake Sirte, which fell to the Takfiri terrorists in February 2015.

Daesh has been taking advantage of the chaos in Libya. The country has been in turmoil since 2011, when NATO and some of its Arab allies intervened militarily, leading to the overthrow of longtime dictator, Muammar Gaddafi, who was later killed.

Libya has had two rival governments since 2014. The two governments reached a consensus on the formation of the GNA in December 2015, after months of negotiations brokered by the United Nations.