By Rogan Ward KWANDENGEZI, South Africa (Reuters) -Rains that have killed around 400 people and left thousands homeless in South Africa this week began pounding the east coast again on Saturday, threatening more flooding and forcing many to take refuge in community centres and town halls. The heavy downpours in Kwazulu-Natal Province have already knocked out power lines, shut off water services and disrupted operations at one of Africa’s busiest ports of Durban, the main eastern coastal city. In Umlazi, one of the country’s largest townships, south of Durban, flood victims huddled under blanke…