Officials say efforts continue to drain a tank that is leaking flammable gas following a massive fire at a Houston-area petrochemical complex, prompting the closure of part of the Houston Ship Channel.

Intercontinental Terminals Company says pumping began Saturday afternoon to extract about 20,000 barrels of the pyrolysis gasoline, known as pygas, from the tank at the Deer Park facility. Vacuum trucks are removing liquid from a ditch.

A section of the Houston Ship Channel was closed Saturday after pygas leaked into the water. Coast Guard Petty Officer Kelly Parker says that remains closed Sunday and that the Guard hopes to reopen the waterway Monday morning.

In this Tuesday, March 19, 2019 photo, shows smoke rising from a fire at the Intercontinental Terminals Company near the Carpenter Elementary School in Deer Park, Texas. Officials have lifted an order to remain indoors after several readings showed that the air quality had improved near a scorched petrochemical storage facility in suburban Houston. City officials in Deer Park lifted the order Thursday and reopened roads around the Intercontinental Terminals Company. But residents living near ITC say they're skeptical of what public officials are telling them. (Jeffrey Fountain via AP)

In this Tuesday, March 19, 2019 photo, shows smoke rising from a fire at the Intercontinental Terminals Company near the Carpenter Elementary School in Deer Park, Texas. Officials have lifted an order to remain indoors after several readings showed that the air quality had improved near a scorched petrochemical storage facility in suburban Houston. City officials in Deer Park lifted the order Thursday and reopened roads around the Intercontinental Terminals Company. But residents living near ITC say they're skeptical of what public officials are telling them. (Jeffrey Fountain via AP)

Parker says 52 vessels are waiting to move, but the channel won't reopen until air and water quality has improved.