Flood waters that swamped vast areas of southern Thailand and inundated its largest city have killed 12 people, officials said Thursday, bringing the flooding death toll from across the country to more than 120.

The government's Disaster Prevention and Mitigation Department said 122 people have died and nearly 6 million residents in 39 provinces in the northern, central, eastern and northeastern regions had been affected by two weeks of heavy floods in October.

But on Thursday, Hat Yai, the urban hub of the south, was coming back to life after the flood waters quickly receded Wednesday. Hundreds of residents gathered to clean up the main streets that were once accessible only by motorboats.

Rows of cars submerged in the flood waters were being removed from the streets and piles of trash taken away by trucks.

"It will take three days to clear up the garbage and make the city livable like before," said Hat Yai mayor Prai Pattano in a telephone interview with The Associated Press. "My only concern is the water service is still not functioning and people don't have normal access to clean water."

Prai said he estimated the damage from the flooding in Hat Yai to be around 7 billion baht ($234 million).

A tropical depression that dumped constant rain on the region Sunday and Monday triggered the flooding in 11 out of 14 southern provinces.

Rail service to the region was partially restored Thursday morning and the airport on Samui island, a popular tourist destination in the Gulf of Thailand, reopened after a temporary shutdown caused by a submerged runway.

Thousands of troops were deployed and Thailand's only aircraft carrier had earlier been sent to help the victims in the coastal provinces.

The deluge in Thailand's south -- along a peninsula it shares with Malaysia -- followed two weeks of heavy floods in October, mostly in central and northeastern Thailand, that killed 107 people. Prime Minister Abhisit Vejjajiva described it as "one of the worst natural calamities" in decades.