Schools will remain closed for students for the rest of the week following Hurricane Sandy, Mayor Bloomberg announced this afternoon.

But he said the city is asking teachers and school staff to report to work on Friday.

Two hundred of the city’s 1,400 school buildings had suffered some damage because of the storm, according to Chancellor Dennis Walcott, who appeared with Bloomberg at the afternoon press conference. Most of the damage was minor, Bloomberg said, but other schools were hit harder.

“There’s an awful lot of schools that have received damage or don’t have power,” Bloomberg said. He added, “Hopefully by Monday everything will be back perfect.”

The 200 damaged schools are currently “not operational,” according to Erin Hughes, a Department of Education spokeswoman. Eighty-six schools currently do not have power, she said.

Hughes said the number would likely change as the department gets more information from schools in Zone A, the mandatory evacuation zone that received significant flooding.

Since the weekend, 76 school buildings have been used as evacuation shelters. In the coming days, Bloomberg said, those shelters will be consolidated into fewer locations.

Bloomberg said the Friday teacher workday would allow teachers and school staff to prepare for students’ return after an interruption of unprecedented length.

Told of Bloomberg’s announcement this afternoon, teachers at Red Hook’s P.S. 15, which was flooded, expressed disbelief that they could be expected to get any work done on Friday.

“Where are we supposed to go?” asked Marie Sirotniak, one of several teachers who had convened to provide assistance to families from the school.

In a press release, Walcott said the department would “provide more information to our staff, including those who may be required to report to a site other than their school.”

More than half of the city’s 23 subway lines are set to run starting Thursday morning, and the city is running special bus lines to help commuters. Yet some parts of the city remain unreachable by public transportation, including the most devastated sections of eastern Brooklyn and Queens and all of Manhattan below 34th Street, where the power has been out since late Monday and is likely to remain that way for several more days.

Most charter schools appeared to be following in the city’s footsteps and canceling classes for the rest of the week. At least one network, Success Academy Charter Schools, had already called off the week’s classes on Wednesday.

About the extended closure, Bloomberg said, “I know it’s an inconvenience for parents.” But he offered a consolation to families who have been “cooped up” this week with their children: City parks should reopen by later this week, and the weather will be perfect for an afternoon outside.