SEOUL, July 17 (Xinhua) -- Security guards of South Korea and the Democratic People's Republic of Korea (DPRK) briefly exchanged fire in the demilitarized zone (DMZ) between the two countries Thursday morning, but there were no casualties on the South Korean side, according to the So uth Korea's military.

　　DPRK soldiers on the central part of the 483-kilometer long border opened what appeared to be machine gun rounds at about 6:10 a.m. (2100 GMT) and South Korean soldiers immediately returned fire, said South Korean Joint Chiefs of Staff.

　　"According to our codes of engagement with enemy, we broadcast warnings and returned fire," said the office in a news release, adding the fire exchange lasted about one minute.

　　It was not immediately known whether there were casualties on the DPRK side.

　　South Korean national news agency Yonhap News quoted South Korean military officials as saying that they later confirmed that a guard post in the DPRK side of the 4 kilometer-wide DMZ fired four machine gun rounds which ricocheted off a concrete barrier around a South Korean guard post. South Korean soldiers shot back 17 rifle rounds, then.

　　The DPRK's military showed "no special movements" following the shooting, South Korean military authorities said.

　　It was the first land border clash since Nov. 27, 2001 when soldiers of both sides exchanged fire. Last late June the navies of the two countries had a skirmish in the Yellow Sea, during which 4 South Korean soldier lost their lives. End