Russian and U.S. officials have traded blame over a vehicle collision Tuesday in northern Syria that left four American service members injured.

Russia’s Embassy in the United States posted a statement on Facebook that Russian Chief of the General Staff Gen. Valery Gerasimov spoke with Chairman of the Joint Chiefs of Staff Gen. Mark A. Milley about the incident. Gerasimov told Milley that U.S troops were already notified about Russian military moving through the area, and said American service members had blocked the Russian patrol “in breach of existing agreements.”

National Security Council spokesman John Ullyot has offered a different account of the situation.

“At approximately 10 a.m. (Syria Time), Aug. 25, a routine Defeat-ISIS Coalition security patrol encountered a Russian military patrol near Dayrick, in northeast Syria,” Ullyot said in a statement on Wednesday. “During this interaction, a Russian vehicle struck a Coalition Mine-Resistant Ambush Protected All-Terrain Vehicle (M-ATV) causing injuries to the vehicle’s crew.”

Ullyot said Russia had engaged in “unsafe and unprofessional actions.”

“Unsafe and unprofessional actions like this represent a breach of de-confliction protocols, committed to by the United States and Russia in December 2019,” he said. Ullyot said the event was de-escalated when U.S. coalition troops left the area.

A bipartisan group of House lawmakers has condemned the recent Russian actions towards U.S. troops.

“We are appalled by reports of Russian military aggression toward U.S. troops on the ground in Syria and strongly condemn their actions,” the statement said. “We strongly urge Russian forces to stop these aggressive behaviors immediately. It is critical that officials at the Pentagon and the White House also clearly communicate to the highest levels of the Russian government and military that actions like this will not be tolerated.”

Russia has been engaged in military operations in Syria since September 2015, in order to shore up the regime of Syrian President Bashar al-Assad.

Russia has a naval facility in the Syrian city of Tartus. The two countries having close economic relations.

The U.S. has supported Syrian rebels fighting against al-Assad and has formed an international coalition to defeat the “Islamic State” terrorist group. President Donald Trump has expressed his desire to withdraw U.S. troops completely from Syria.

Tensions between the U.S. and Russia have been increasing in recent months. In June, Russian and U.S. warships almost collided in the Pacific, with both sides trading blame for the incident. Earlier that month, a Russian aircraft intercepted a U.S. aircraft multiple times on the same day while flying in international airspace over the Mediterranean Sea.