North Korea followed up with an ultimatum sent via military hotline that gave the South 48 hours to dismantle loudspeakers blasting propaganda messages across the border or face further military action.
The South's defence ministry dismissed the threat and said the broadcasts would continue.
Direct exchanges of fire across the inter-Korean land border are extremely rare, mainly, analysts say, because both sides recognise the risk for a sudden and potentially disastrous escalation between two countries that technically remain at war.
In a detailed press briefing later in the day, the South's defence ministry said the nuclear-armed North initially fired a single artillery round over the border shortly before 4:00pm (0700 GMT).
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Minutes later it fired several more in the rough direction of one of the South's loudspeaker units, but the shells fell short on the South's side of the demilitarised zone (DMZ) -- a four kilometre-wide buffer area straddling the actual frontier line.
As a preventive measure, local South Korean residents in Yeoncheon county some 60 kilometres north of Seoul were ordered to evacuate their homes for nearby shelters.
South Korean troops were placed on maximum alert, while President Park Geun-Hye chaired an emergency meeting of her National Security Council and ordered a "stern response" to any further provocations.
Later in the day, North Korea convened an emergency meeting of its powerful Central Military Commission, South Korean news agency Yonhap reported the North's state media as saying.
"Such provocative actions heighten tensions, and we call on Pyongyang to refrain from actions and rhetoric that threaten regional peace and security," State Department spokesperson Katina Adams said of North Korea's shelling of the South.
"The United States remains steadfast in its commitments to the defense and its allies, and will continue to coordinate closely with the Republic of Korea," the news agency quoted her as saying.