Original sentence: In the early morning of January 19, 1974, Vietnamese troops from the HQ-5 landed on Duncan Island and came under fire from Chinese troops after opening fire first on the Chinese while advancing toward the shores
Edited sentence: In the early morning of January 19, 1974, Vietnamese troops from the HQ-5 landed on Duncan Island, opening fire on the Chinese troops while advancing towards the Chinese shores, this caused the Chinese to return fire from their positions along the shores