Thailand officials warned millions of residents in the capital Bangkok on Friday to move their belongings to higher ground, after the government ordered the opening of floodgates that have so far kept the water out of the city.

Thailand's Prime Minister Yingluck Shinawatra on Thursday ordered the gates open to try to drain the waters that have already flooded Bangkok's northern suburbs.

Ms. Yingluck told the capital city to brace for floods, saying the government “cannot stop the water forever,” and that the canals running through the city to the Gulf of Thailand could overflow into the streets.

Many in the city are rushing to stock up on food and drinking water while those in the flooded north have already fled their homes.

Months of heavy monsoon rains have soaked large parts of Southeast Asia, killing 320 people in Thailand. Millions have been forced from their homes. Hundreds have also died in Cambodia, Laos, and Vietnam.