PHILADELPHIA (AP) - A small army of electricity restoration crews labored Friday to reconnect more than 250,000 customers in Pennsylvania and Maryland who lost power in an ice storm, and utility companies warned some will have to wait several more days.

The lion's share of the outages remained in the Philadelphia suburbs, where many schools were closed for a third day, and a PECO spokesman said work was continuing around the clock. PECO accounted for about 220,000 outages Friday night."That number is coming down throughout the course of the day," said PECO spokesman Fred Maher. "We are preparing people for the fact that some folks will be without power over the weekend."Severe cold weather that gripped the mid-Atlantic on Friday was expected to remain in place for days, and forecasters said light snow was possible over the weekend.Utility companies reported about 240,000 customers without power in Pennsylvania, most of them in the five-county Philadelphia area. In Maryland, service had been restored to all but about 16,000 homes and businesses.There has been progress: More than a million outages had been attributed to the storm.Systems engineer John Bowman said he has been buying $6 packages of firewood at a neighborhood hardware store, planning to burn them in the coming days to keep the temperature in his Downingtown home high enough to prevent damage to water pipes. He said he was told it may be Sunday before his power is restored."With the way the sun's been warming up the house, I don't want to use those rations yet," Bowman said.Rachel Ezekiel Fishbein, of Elkins Park, lost power before dawn Wednesday, a day after she spent about $300 on groceries in anticipation of the storm. Although she tried to save some perishables by packing them outside in a cooler in the snow, she wasn't optimistic on Friday morning."I'm thinking that most of that food has probably gone bad by now," Fishbein said from her sister-in-law's house.Authorities urged people to be careful when using space heaters and other methods to heat their homes. The Pennsylvania Emergency Management Agency said four confirmed cases of carbon monoxide poisoning and a fifth suspected case were reported at a hospital in the Philadelphia suburbs on Wednesday night.Amtrak restored full service between Philadelphia and Harrisburg on Friday morning after tracks were cleared of fallen trees and debris.The storm, which generated headaches for motorists and homeowners, also created a boom in business for Amspacher Tree Service in York, where the ice coated snowy trees and forced down branches. The company was concentrating on getting trees off homes and cars and telling customers their crews will return later to clean it all up."We're going pretty crazy," Louanna Amspacher said. "We went from a dozen calls a day, at most, to a hundred calls."AP writer Kathy Matheson contributed to this report. Scolforo reported from Harrisburg.