TEXAS CITY, Texas (AP) — No timetable has been set to reopen the Houston Ship Channel after nearly 170,000 gallons of tar-like oil spilled into the busy Texas waterway.

But more help was being called in Monday to contain the spill and protect shorebird habitat.

The Coast Guard says a barge carrying about 900,000 gallons of oil collided Saturday with a ship, spilling about a fifth of it into one of the world's busiest waterways for moving petrochemicals.

By Sunday, oil had been detected 12 miles offshore in the Gulf of Mexico, and as many as 60 vessels were waiting to get in or out.

Environmental groups say the spill occurred at a sensitive time. The channel has important shorebird habitat on both sides and tens of thousands of wintering birds are in the area.

(Story by: Michael Graczyk, Associated Press)