The Democratic People's Republic of Korea (DPRK) announced Thursday that it will scrap an inter-Korean agreement preventing accidental naval clashes with South Korea.

The decision is one of the seven measures announced by Pyongyang in response to South Korean sanctions.

The measures announced by the general staff of the DPRK also includes banning South Korean ships, planes and other vehicles from passing through the territorial waters, airspace and land, and "the people of the South Korean authorities" from entering the DPRK.

The announcement came as tensions escalated between the DPRK and South Korea following the sinking of a South Korean warship near the maritime border.

The following is a timeline of the South Korean ship sinking incident:

On March 26, the South Korean naval vessel Cheonan with 104 crew members onboard sank into the waters off the west coast of the Korean Peninsula, killing a total of 46 sailors.

On March 27, General of the South Korean Navy Lee Ki-shik said that the 1,200-ton warship Cheonan went down after an unexplained explosion ripped a hole in the ship's bottom.

On March 28, a senior South Korean official said that it appeared to be unlikely that the DPRK had anything to do with the naval ship sinking.

On April 17, the DPRK denied that it sank the South Korean naval vessel amid growing speculation in the South that the ship had been hit by a DPRK torpedo, saying the sinking of the Cheonan was the fault of the South Korean military.

On May 18, an unnamed South Korean military official said that the traces of explosives from the wreckage of the Cheonan were identical in composition to those used in DPRK torpedoes collected seven years ago.

On May 19, South Korean Foreign Minister Yu Myung-hwan said that involvement of the DPRK in the deadly sinking of the South Korean warship was "obvious."

On May 20, a multinational team of investigators concluded on May 20 that the South Korean navy warship was torpedoed by a DPRK submarine, and that the torpedo was manufactured in the DPRK.

The conclusion was rejected by the DPRK, which warned that any retaliation by South Korea would lead to an "all-out" war.

On May 23, a senior government official said South Korea was planning to seek an additional resolution on the DPRK at the United Nations Security Council.

Another official at the presidential office also hinted at bringing the case before the UN Security Council and seeking a fresh resolution.

On May 24, South Korea unveiled a series of punitive measures against the DPRK over the sinking of the naval warship.

South Korean President Lee Myung-bak warned in a nationally televised speech that the country would resort to measures of self-defense if the DPRK further wages aggression.

As part of the measures, the president said DPRK-flagged ships would no longer be allowed to make passage through any of the shipping lanes in South Korean waters.

The country would also put trade and exchanges with the DPRK on hold.

Condemning the DPRK for violating the United Nations Charter and the Korean War Armistice Agreement, Lee said his government will refer the incident to the U.N. Security Council.

On May 25, a spokesman of the Committee for the Peaceful Reunification of Korea announced that the DPRK would sever all relations with South Korea.

The spokesman said the DPRK decided to take "resolute measures" to totally freeze inter-Korean relations, abrogate the agreement on non-aggression between the two sides and completely halt inter-Korean cooperation.

The DPRK said that, among the eight measures to be taken at the first phase, all the relations with South Korea would be cut off, and the work of the Panmunjom Red Cross liaison representatives would be completely suspended.

It added that the South Korean personnel in the Kaesong Industrial Zone would be expelled.