It is "reasonable and legal" for Chinese fishing boats to operate in the waters of the Whitsun Reef in South China Sea, China's foreign ministry said on Monday (December 4), after the Philippines deployed vessels to monitor what it said was an "illegal" presence of the boats.

The Philippine Coast Guard said on Sunday (December 3) it has monitored the "illegal presence" of more than 135 Chinese maritime militia vessels at the reef in the South China Sea within the country's exclusive economic zone (EEZ). It said in a statement its chief has ordered that patrols be carried out in the vicinity of Whitsun Reef, which Manila calls the Julian Felipe Reef.

Speaking at a news conference in Beijing, Chinese foreign ministry spokesperson Wang Wenbin called the area "a very important operating area and shelter for Chinese fishing boats", while warning the Philippines not to make "irresponsible remarks".

An international tribunal invalidated China's claim to 90% of the South China Sea in 2016, but Beijing does not recognize the ruling. China has built islands in the disputed waters in recent years, laying air strips on some of them. — Report from Reuters