Seoul, South Korea ? North Korea recently violated the 1953 armistice that ended the Korean War by bringing machine guns into the buffer zone separating the two Koreas, the U.N. Command said Friday.

The U.N. Command said an investigation confirmed reports by South Korean soldiers that North Korean troops brought 7.62mm machine guns into the Demilitarized Zone on six occasions from Dec. 13 to Dec. 20.

The North Koreans set up the weapons 100 to 400 yards north of the border, or Military Demarcation Line, the U.S.-led command said in a statement. The two Koreas have been working on a cross-border railway in the area.

“The weapons were apparently removed at the end of each day,” said the command, which oversees terms of the armistice in the southern half of the Demilitarized Zone.

The command requested a meeting with North Korean counterparts to discuss the issue on Thursday, but it said communist officials refused to accept the request.

North Korea routinely violates terms of the armistice that govern conduct inside the DMZ, according to U.S. military officials.

North Korea occasionally accuses U.S. and South Korean soldiers of similar types of violations.