North Korea has fired around 90 additional artillery rounds into the maritime buffer zone in the East Sea on Tuesday in violation of the inter-Korean military accord. 

The Joint Chiefs of Staff (JCS) said Tuesday the North began firing the rounds from Kosong County in Kangwon Province from 10 a.m. and continued into the afternoon. 

The JCS said they landed in the East Sea buffer zone, lying north of the de-facto maritime inter-Korean border, the Northern Limit Line, amounting to the violation of the September 19, 2018 military agreement. 

On Monday, the North also fired 130 artillery shells into both eastern and western maritime buffer zones.

The artillery barrages came in an apparent protest against ongoing live-fire drills by the South and the U.S. 

A spokesperson of the General Staff of the North's Korean People's Army said that the firing of multiple rocket launchers and howitzers by the "enemy" was again observed in the border area from 9:15 a.m. on Tuesday.

The spokesperson said an emergency order was issued commanding front-line troops to fire artillery in response.

Although the spokesperson called for an immediate stop to what it called provocative military action by South Korea and the U.S., the drill is routine training that does not violate the 2018 inter-Korean accord, which Seoul emphasized as the alliance continued their scheduled exercise in Cheorwon, Gangwon Province.