The U.S. sent two warships to a disputed shoal in the South China Sea, where two Chinese ships recently collided while chasing a boat from the Philippines.

A US Navy guided-missile destroyer performed a so-called Freedom of Navigation operation (FONOP) near disputed Scarborough Shoal in the South China Sea on Wednesday, just two days after two Chinese military vessels collided while chasing a Philippine Coast Guard ship in nearby waters.

The U.S. deployed two warships Wednesday to a disputed South China Sea shoal where two Chinese ships collided earlier in the week while trying to drive away a smaller Philippine ship in a high-seas incident that raised alarms about maritime safety.