BEIRUT — Syrian government forces and their allies have captured a wide area from the Islamic State group in the country’s center, two days after besieging it, an opposition monitoring group and a Syrian military arm said Saturday.

The government-controlled Syrian Central Military Media and the Britain-based Syrian Observatory for Human Rights say troops and their allies are now in control of the area between the central town of Sukhna and Shaer to the west. On Thursday, troops surrounded the area of 2,000 square kilometers (772 square miles) in the Syrian desert, widely referred to as Badia.

In recent months, Syrian troops and allied militiamen have advanced on three fronts against IS under the cover of Russian airstrikes. One of their main targets is the contested eastern city of Deir el-Zour, where the militants have imposed a siege for years on a small government-held pocket.

SCMM said military experts are now dismantling explosives left behind by the extremists in Badia.

IS once controlled nearly half of Syria, but has been driven back by an array of Syrian forces, including a Kurdish-led force backed by U.S.-led airstrikes. Now IS controls less than 30 percent of Syria and is expected to lose more in the coming months.

In the country’s north, where one of the government attacks is taking place, a Syrian journalist was killed Saturday while covering the fighting with IS.

The state-run Syrian Arab News Agency said its correspondent Mohammed Nasr, 34, was killed in the northern province of Raqqa, without giving further details.

Syria, which has been mired in a complex civil war for more than six years, is one of the most dangerous places for journalists. The New York-based Committee to Protect Journalists says 14 were killed in 2016 alone. The latest death brings this year’s toll to four.