SAVANNAH, Ga. (AP) — Firefighters battled a giant blaze fueled by 5,600 tons of rubber Saturday at the Port of Savannah, where a towering column of black smoke could be seen from miles away.

By late Saturday, the fire department said its crews had contained the fire, but it could take a while for the flames to burn out inside a warehouse covering 226,000 square feet at the port’s Ocean Terminal just west of downtown Savannah.

“It is contained,” Savannah Fire and Emergency Services spokesman Mark Keller said late Saturday afternoon, after the fire had burned for at least five hours. “Will it burn all night? There’s no telling. It’s solid blocks of rubber that are burning.”

Keller said firefighters were surrounding the warehouse with hoses on three sides and using industrial pumps to suck water from the Savannah River and blast in through water cannons. Crews will continue soaking into the night and Sunday if necessary.

The cause of the fire wasn’t immediately known, but all port workers were accounted for and unharmed.

No mandatory evacuations have been ordered. Authorities are asking people in the downtown historic district, Savannah’s tourism hub, to stay indoors as much as possible to limit exposure to smoke.

“Please limit the time you’re out,” Keller said, adding he didn’t expect people to cancel dinner reservations or shopping trips. “If you’re finished at the restaurant or finished with shopping, go back to your hotel room or go home.”

Keller said firefighters probably won’t be able to get close enough to investigate the cause until Sunday.

“Solid rubber blocks, they’re going to burn and we’re going to keep putting water on it,” Keller said. “We’ll just do it until the fire’s out.”

Savannah-Chatham County police closed some streets near the port terminal and smoke slowed traffic on the Talmadge Bridge that spans the Savannah River to South Carolina. Police also asked a few hotels near the port terminal and the Savannah College of Art and Design, which has buildings in the area, to either evacuate or keep people inside.

“We’re not worried about the fire getting over there at this point,” said police spokesman Julian Miller. “It’s the smoke. It’s going to be heavy, oily and ugly.”

Robert Morris, spokesman for the Georgia Ports Authority, said the burning area contained about 5,600 tons of imported raw rubber used in manufacturing.

“The warehouse is full of rubber, so it’s a rubber fire,” he said.

June Kramarczyk of Bluffton, S.C., and her husband were traveling to Savannah when they saw the smoke plumes rising in the distance. They pulled over once they reached the river to get a better look.

“It’s covering the whole sky in front of us, almost as if there was a volcano going off,” Kramarczyk said. “We could see the smoke from 15 miles away. My husband said, ‘That’s got to be a huge fire.’”

Morris said smoke could be seen from Tybee Island, about 18 miles east of the port terminal.

The Port of Savannah is the nation’s fourth-busiest seaport for containerized cargo. The Ocean Terminal, which covers 200 acres, handles farm equipment and other heavy machinery as well as automobiles and bulk goods such as wood products and steel.