SEOUL, South Korea (AP) — Residents on a front-line South Korean island say they've been evacuated to shelters following an exchange of artillery fire between North and South Korea.

South Korea says it has returned fire into North Korean waters Monday after shells from a North Korean live-fire drill fell south of the rivals' disputed western sea boundary.

Resident Kang Myeong-sung said in an interview from a shelter on Yeonpyeong island that residents were huddled in shelters.

Kang says he hasn't seen any fighter jets, but he can hear the boom of artillery fire. In 2010, North Korean artillery killed four South Koreans on Yeonpyeong.

South Korean officials say no shells from either side were fired at any land or military installations.