Israeli troops raided the Askar refugee camp in this West Bank city Tuesday, rounding up hundreds of its male residents and detaining them in a high school courtyard, witnesses said. The raid came just a day after Israeli troops withdrew from Nablus after more than a week of a series of searches and arrests in the city's center. The army frequently operates in Nablus, the West Bank's largest city, saying it is a center of resistance activity. Dozens of Israeli troops, backed by army jeeps and armored vehicles, entered the camp early Tuesday morning, enforced a curfew, and sealed off all entrances to the camp, witnesses said.