Complex sentence: As Kuomintang troops neared and entered the city, which had many foreign residents, the Kuomintang troops targeted and looted foreign properties, doing much damage and killing and injuring many foreign personnel.
Split into simpler sentences: As Kuomintang troops neared and entered the city, which had many foreign residents. The Kuomintang troops targeted and looted foreign properties, doing much damage and killing and injuring many foreign personnel.