DAISETTA, Texas (AP) - A large sinkhole swallowed up oil field equipment and some vehicles Wednesday in southeastern Texas and continued to grow. There were no reports of injuries or home damage.

"Right now we're not concerned about any kind of explosion or any kind of hazard," said Tom Branch, coordinator of the Liberty County Office of Emergency Management.

"We are monitoring some other things around the area to make sure everyone's OK."

Television news footage showed a tractor, oil field equipment and telephone poles falling into the sinkhole as it grew near Daisetta, a community of about 1,000 people northeast of Houston.

Vehicles from a nearby state highway were being diverted, said Mary Credeur, a dispatcher with the Daisetta Police Department.

"We're just going to shut the road down and see how big it gets. Hopefully it will stop," Branch said.

The sinkhole was believed to be at least 600 feet long and 150 feet deep.

"It's a huge hole in the ground, and it's still cracking," Credeur said.

Officials are trying to determine what caused the sinkhole, but its history as a once-booming oil town might be to blame.

Officials say the ground might have caved in because of the collapse of an old salt dome where oil brine and natural gas are stored underground. Daisetta sits on a salt dome, one of the most common types of traps for oil.