China and the Philippines on Monday defended their claims to a disputed reef in the South China Sea, after Manila accused Beijing of seeking to “intimidate and harass” with a state media report that suggested the area had been seized.

The competing claims are reigniting tensions in the South China Sea and coincide with joint military drills between the U.S. and the Philippines.

The standoff over Sandy Cay, which lies close to military outposts built by both Beijing and Manila, was the latest between the two nations.