Tensions between North and South Korea have boiled over, with shots being fired by both sides leaving at least two marines dead and wounding more than 13 others.
The conflict came to a head on Tuesday when the North fired artillery at an island belonging to the South in the Yellow Sea, according to military officials.
At least 100 rounds fell on Yeonpyeong, which houses a military garrison and is home to some 1,600 residents, according to the Yonhap news agency. However, the Defense Ministry has not confirmed how many rounds actually struck the island.
In response to the attack, the South Korean military fired more than 80 rounds into North Korea and launched fighter jets. The exchange of artillery lasted about an hour, CNN reports.
Images of smoke spewing into the sky over the small island were broadcast on Yonhap television, and showed several houses on fire. Residents have begun to flee to the South Korean mainland some 90 miles away.
"I was at home when I was surprised by the sounds of bomb explosions," a 35-year-old resident told the Korean news agency. "As I stepped out of my home, I saw the entire village had already turned into a sea of fire."
The attack began around 2:34 p.m. local time, a military official told Yonhap. Tensions between the neighboring nations have worsened since earlier this year, when a North Korean torpedo sank a South Korean navy ship, killing 46 people. It was also revealed this weekend that the North has secretly constructed a facility that allows it to produce low-enriched uranium.
The artillery fire followed a routine military drill by the South near Yeonpyeong island, Yonhap reports. The nine-day practice occurs annually at the site and started on Monday.
"North Korea's indiscriminate artillery attack on Yeonpyeong Island is a clear military provocation on the Republic of Korea," Hong Sang-pyo, senior secretary for public affairs at the presidential office Cheong Wa Dae, said in a statement. "Furthermore, recklessly shelling against civilians can never be tolerated."
The United States, which has tens of thousands of troops stationed in South Korea, was also quick to blast the North Korean attack.
Read More:North Korea bombs South Korea's Yeonpyeong island; 2 dead, 13 wounded in attack: report
