GULFPORT, Miss. (AP) -- Isaac inundated low-lying areas along Mississippi's Gulf Coast on Wednesday as hurricane-driven water rose several feet in some spots while thousands waited out the storm in shelters.

Officials in Hancock and Harrison counties extended curfews until 9 a.m. to keep off roads until after the high tide passes at around 8 a.m.

Harrison County emergency management director Rupert Lacy said the storm surge coupled with the high tide could lead to more extensive flooding.

Lacy said coastal rivers also were beginning to rise from the rainfall.

More than 15,000 people remained without power in coastal areas.

AP-WF-08-29-12 1148GMT