The U.S. has detected worrisome signs of more substantial participation in Russia’s war in Ukraine from an influential force: China.

U.S. military forces shot down a flying object over Lake Huron on Sunday, Congress members said, marking the fourth takedown of an aerial vessel over North America since last Saturday, when fighter jets destroyed a suspected Chinese spy balloon first spotted over U.S. territory on January 28.

The downing of a suspected Chinese surveillance balloon by the U.S. military was met by lawmakers with a mix of praise for the safe and successful operation, criticism for it not happening sooner and concern over what intelligence may have been gathered and how to prevent something like this from happening again.

The General Staff of Ukraine’s Armed Forces said that an additional eight Russian tanks had been destroyed in a single day since the last operational update on Saturday morning, bringing the total number of Russian tanks destroyed since the invasion began on February 24, 2022, to 3197.

The speaker of the lower house of Russia’s parliament warned Sunday that countries supplying Ukraine with more powerful weapons risked their own destruction, a message that followed new pledges of armored vehicles, air defense systems and other equipment but not the battle tanks Kyiv requested.