Tensions flared between Russia and the United States as the Russian military reportedly seeks to expand its presence in U.S.-controlled northeastern Syria, news outlets reported this week.

The latest flare-up follows the Russian military’s reported attempt to build a base near the Turkish and Iraqi borders last week. President Vladimir Putin has ordered talks with Russia’s ally Syria on cementing Moscow’s presence with additional military facilities in the conflict-torn country.

U.S. and Russian forces squared off in two tense encounters in the same area on Tuesday and Wednesday, the Mideast news website Al-Monitor reported, citing local monitoring groups and news agencies.

Villagers reportedly protested against a Russian patrol Tuesday near the northeastern Syria border town of Al-Malikiyah (Derik) as U.S. convoys awaited them nearby. On Wednesday, a Russian patrol was said to have come toe-to-toe with an American convoy outside Derik, blocking civilian traffic for hours.

AFP video showed U.S. and Russian military patrols parked on a road as local civilians protested the Russian presence. 

The latest standoffs follow a series of similar incidents reported in northeastern Syria earlier this year.

“This is not a sustainable situation,” tweeted Brett McGurk, the former U.S. envoy for the U.S.-led coalition against Islamic State.

American officials have previously accused Russia of violating the terms of de-confliction in what they characterized as an attempt to challenge the U.S. presence there.

Russia, a staunch ally of the Syrian government, launched a military air campaign in Syria in 2015 to help Damascus recapture parts of the country from rebels.

Moscow has long insisted that the U.S. military presence in Syria is illegal. 

The U.K.-based Syrian Observatory for Human Rights monitoring group said Thursday that Russia withdrew from the village of Qesirdib where it had attempted to set up a new base.