Communist forces came within shelling distance of Phnom Penh .
Communist forces captured the former royal capital of Oudong in March : they ' evacuated ' its population -- shooting government officials and teachers -- and destroyed or burnt much of the town .
Communist forces came within shelling distance of Phnom Penh , and captured the former royal capital of Oudong in March : they ' evacuated ' its population -- shooting government officials and teachers -- and destroyed or burnt much of the town .