Boil-water order for New Orleans until 3 p.m. Sun.

NEW ORLEANS — Mayor Mitch Landrieu says New Orleans' most widespread boil-water order since Hurricane Katrina will continue at least until 3 p.m. Sunday, because that's how long it will take to test for bacteria.

The order covers most of the city, affecting more than 300,000 people.

Landrieu says crews took water samples from 28 spots around the city's east bank - but the samples need 24 hours to incubate.

Officials say the boil order was called as a precaution after a power failure late Friday at the city's main treatment plant - including its three backup power systems - caused low water pressure throughout the east bank.

Electricity was restored around midnight, and water pressure is back to normal.

The city's west bank was not affected.