Thai officials said Sunday the death toll from Thailand's worst flooding in 50 years has reached 506.

The officials said the flood waters were threatening Bangkok's largest outdoor shopping zone, the famed Chatuchak market, and the subway system, and new evacuations were taking place in the city 12 million.

Local authorities ordered evacuations in 10 of Bangkok's 50 districts, and partial evacuations in at least five others. But many people have chosen to stay behind to protect their homes and businesses.

Thailand's Prime Minister Yingluck Shinawatra on Saturday assured the residents of Bangkok that flooding in the city center would be minor and brief.

In her weekly radio address, Ms. Shinawatra said a six-kilometer-long flood wall of huge sandbags had been completed and drainage systems would keep the city's economic and political center mostly dry.

The flood waters have affected more than 3 million households across three quarters of the country's provinces. The estimated financial damage is already in the billions of dollars. The waters have so far inundated almost 10,000 factories, resulting in the loss of 660,000 jobs.

Despite the damage, Thai central bank governor Prasarn Trairatvorakul said economic recovery is possible if the waters recede by early December and domestic spending is revived.