A busy shipping lane to the port of Houston, Texas was closed Monday as clean up crews struggled to remove oil that spilled in a weekend barge crash.

The barge loaded with a million gallons of tar-like "bunker" oil collided with a ship Saturday, and the US Coast Guard said that some 168,000 gallons of oil had spilled in the accident.

Cleanup agencies deployed more than 69,000 feet of containment boom near the crash site "and along sensitive shorelines in the area," the Coast Guard said in a statement.

Some 24 vessels "are actively working to skim the oil," the Sunday statement read.

Workers siphoned the remaining oil from the barge's damaged compartment into a second barge, and the damaged vessel was later moved to a shipyard, Texas state officials said.

The Houston Ship Channel "remains closed to traffic," the statement read.

Coast Guard said let two cruise ships through the area on Sunday "to minimize inconvenience to the thousands of passengers aboard and limit economic impacts from the spill.

"However, neither vessel will be allowed to leave the port again until deemed safe to do so," they warned.

According to local media, the oil slick extends some 12 miles into the Gulf of Mexico and south along Galveston Island.

Bunker oil, also known as fuel oil, is a heavy, extremely crude and highly polluting form of oil. Also known as fuel oil and "bottom of the barrel" oil, bunker oil is used to power ship engines and for household heating.

As of Sunday afternoon fewer than 10 birds covered in oil were seen, picked up and taken "to a wildlife rehabilitation facility" especially set up to deal with the spill, the Coast Guard said.

Responders are working with Texas Parks and Wildlife and the US Fish and Wildlife and Wildlife Response Services to deal with other "impacted wildlife."