At dawn on Sunday, 25 June, Syngman Rhee launched a sudden attack which took the North Koreans by surprise. His forces crossed the 38th parallel at several places and captured Haeju, some miles to the north on the road to Pyongyang. The North Koreans staged a counter-offensive and the South Koreans threw down their arms and fled. The North Koreans then drove on across the parallel and staged a full-scale invasion of South Korea.On 28 June, Chou En-lai, the Foreign Minister of the Peking Government, declared that the US had instigated Syngman Rhee to attack the North Koreans in order to create a pretext for sending the Seventh Fleet to Formosa, an act which he denounced as armed aggression against Chinese territory.
https://www.marxists.org/history/international/comintern/1951/korea.htm
Do any official documents confirm that South Korea attacked first?
