South Korea's Coast Guard will sternly deal with illegal Chinese fishing boats whose numbers have been sharply increasing near the exclusive economic zone in the West Sea to the tune of around 360 per day. 

It marks an 80 percent surge from 199 last month. 

Chinese vessels are found to be intruding into Korean waters mostly at night to fish illegally. 

The Coast Guard uses water cannons against the intruders. But oftentimes, clusters of 50 to 60 Chinese boats operate together. Authorities will now step up their response including the use of firearms. 

One official vowed a stringent response within the boundaries permissible by law against illegal foreign vessels trespassing into South Korea's sovereign waters. 

This year, some 34-hundred Chinese boats were expelled from areas near the EEZ, but not one has been seized.