South Korea said Friday it had deployed advanced weapons-tracking radar systems on islands near its disputed Yellow Sea border with North Korea following last week's artillery barrages by the North.

Defence Minister Kim Tae-Young told lawmakers the AN/TPQ-36 Firefinder systems had been set up on Baengnyeong and Yeonpyeong islands.

"A few days ago, deployment of anti-artillery radar systems was completed," the minister was quoted as saying by Yonhap news agency.

The system is designed to determine where incoming artillery and rocket fire originated, to allow for a possible counter-attack.

After declaring two "no sail" zones, the communist state last week fired 370 shells into the sea near the border over three straight days, heightening tensions on the Korean peninsula.

Seoul's military said Wednesday the North had designated another two "firing zones" in the area, effective for four days from Friday, raising the prospect of more artillery fire.

The North said its salvoes last week were part of a routine winter exercise but South Korea and the United States described them as provocative.

The Yellow Sea border was the scene of deadly naval battles in 1999 and 2002 and of a firefight last November which left a North Korean patrol boat in flames.