China is stepping up patrols in the waters off the coast of Taiwan’s Kinmen archipelago, days after two of its fishermen drowned while being chased by the Taiwanese coast guard, which accused the boat of trespassing.

The Chinese coast guard’s Fujian division will regularly monitor the waters off the southern coast of the city of Xiamen—a few kilometers from Kinmen—to strengthen maritime law enforcement, said the coast guard’s spokesman, Gan Yu, on Sunday.