(CNN) -- Forces loyal to Alassane Ouattara took control of state-run television and attacked the residence of Laurent Gbagbo on Friday as Ivory Coast's bloody, four-month battle for political power appeared to enter its final stages . Artillery and mortars joined the cacophony of gunfire Friday in Abidjan, the nation's commercial center and largest city, witnesses said. French and United Nations troops beefed up their presence on the streets to fill a security vacuum. "The situation on the streets has deteriorated to such an extent that it's just become too dangerous to go outside," said Henry Gray, a field coordinator with the humanitarian medical group Doctors Without Borders, who called his organization while in lockdown. "There's a lot of pillaging and looting going on, and if you're out on the streets, you're basically a target."
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NEW: At least 800 people were killed Tuesday in the Ivory Coast, the Red Cross says
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NEW: A witness says, "If you're out on the streets, you're basically a target"
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Laurent Gbagbo has refused to cede power since a disputed November election
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Forces loyal to Alassane Ouattara attack Gbagbo's home and take control of state TV
@placeholder declared evening-into-morning curfews for Friday and Saturday in Abidjan.