North & South Korea Fire Artillery At Each Other

It's getting increasingly tense around the Korean peninsula. On Monday, at around noon local time, North Korea fired around 100 artillery shells across the western sea border into South Korean waters. South Korea was having none of it, and responded by firing 300 shells back into North Korean waters.

Early on Monday, Pyongyang announced that it would be carrying out live-fire drills in seven areas just north of the disputed maritime border. North Korea's military faxed a message to the South's navy to warn that the exercises were about to take place. Over more than three hours, North Korea fired around 500 artillery shells, around 100 of which ended up in South Korean waters.

South Korea had already warned that if any shells landed in their waters then they would fire back. And fire back they did, with 300 shells.

Meanwhile, residents of Baengnyeong, a border island belonging to South Korea, were evacuated into shelters during the exchange of fire. However, officials say that no shells hit land either side of the Northern Limit Line, and nobody was injured.

The Northern Limit Line was drawn by the UN after the Korean War, but Pyongyang has never officially recognized it, making this area a hotly-disputed territory.

Back in 2010, North Korean artillery fire killed four South Koreans on the border island of Yeonpyeong, and earlier that same year a South Korean warship sank near Baengnyeong island, causing the death of 46 sailors. Seoul claims the ship was torpedoed by Pyongyang, but North Korea denies any involvement in the incident.

Recently, relations between the two Koreas have taken a turn for the worse. At the beginning of the month North Korea launched four short-range missiles over the Sea of Japan, apparently in protest of the annual joint American and South Korean military exercises that had just commenced.

Last Wednesday, apparently in response to comments made by South Korean President Park Geun-hye that Pyongyang's nuclear missiles could easily end up in the hands of terrorists, North Korea decided to fire two medium-range Rodong ballistic missiles into the sea off its east coast. This was a clear violation of UN Security Council resolutions that call for a complete suspension of North Korea's ballistic missiles and nuclear program.

On Sunday, North Korea said it "would not rule out" carrying out a new nuclear test, although it did not specify what that new test would entail.

"The U.S. had better ponder over this and stop acting rashly," Pyongyang's foreign ministry said in a statement conveyed by KCNA, a state-run news agency, according to CNN.

In response to Monday's exchange of fire, China's Foreign Ministry spokesman Hong Lei has called for both sides to remain calm and avoid doing anything else to escalate tensions. Although China has traditionally joined with the UN in condemning Pyongyang's provocative acts, such as test-firing missiles, on this occasion the nation has instead chosen not to single out North Korea but rather ask both sides to cool off.

As neither side is directly targeting China, there's little China can do to intervene, other than urge the two nations to take a deep breath and a step back.