A senior Russian general on Tuesday criticized the U.S.-led coalition fighting Islamic State militants for allegedly targeting Syria’s infrastructure — including a key dam — in territory held by the Sunni extremist group.

Col. Gen. Sergei Rudskoi of the military’s General Staff accused the coalition of trying to “completely destroy critical infrastructure in Syria and complicate post-war reconstruction as much as possible.”

However, the U.S.-backed Syrian opposition force has insisted it is taking care to preserve vital infrastructure as it steps up military operations in northern Syria ahead of a push on Raqqa, the city that is the Islamic State’s group main stronghold and de facto capital.

Rudskoi further claimed that coalition jets had destroyed four bridges over the Euphrates River in Syria and hit the Tabqa dam to the west of Raqqa.

The collapse of the dam would case an “ecological catastrophe” and lead to “numerous” civilian deaths, he said.

On Monday, the U.S.-led coalition reiterated that it is taking every precaution to ensure the integrity of the dam. “To our knowledge, the dam has not been structurally damaged,” it said on its Twitter account.

A spillway north of the structure is under control of the U.S.-backed and Kurdish-led opposition group known as the Syrian Democratic Forces, and can be used to relieve pressure behind the dam, the coalition told The Associated Press in an email on Sunday.

Engineers who used to work at the site have expressed doubt that the spillway could accommodate the water flow but said it will still take at least a month for the lake to reach critical levels if the gates are not opened. IS has warned that the dam’s main gates are out of service, causing water levels to rise behind the levee.

Pressure on IS has intensified in recent months as the group has seen a series of battlefield reverses amid Syria’s bloody 6-year civil war.

With SDF forces to the north and west of the city of Raqqa, a push on IS’s de facto capital is shaping up to be the next major battle in Syria. Last week, U.S. aircraft ferried hundreds of SDF fighters, as well as American artillery and military advisers, behind IS lines in preparation for the battle.

President Bashar Assad’s government has objected to U.S. involvement, saying that American forces are unauthorized to be on Syrian soil. For its part, Moscow prefers seeing Syrian government forces leading the assault on Raqqa.

Activist groups said Monday the city itself has been without electricity and municipal water for the past three to five days.

The Britain-based Syrian Observatory for Human Rights said the cuts are due to the fighting around Tabqa Dam, 40 kilometers (25 miles) west of Raqqa.

Rudskoi said Tuesday that Syrian government forces, with Russian military assistance, are making progress against IS. Russia has been Assad’s main backer and has played a key role in turning the tide of war in his favor.

Syrian forces now control of territory up to 16 kilometers (13 miles) around the historic town of Palmyra, Rudskoi said, adding that they recently seized control of high ground held by IS along a highway connecting Palmyra and the capital, Damascus.

Syrian troops fully recaptured Palmyra earlier this month after a push that saw the IS’s defenses crumble and their fighters flee in the face of artillery fire and intense Russia-backed airstrikes. The Syrian government had seized the town from Islamic State militants last March, only to lose it again 10 months later.

(AP)