The sudden appearance of Zakaria Zubeidi, the 29-year-old militant leader, and at least 20 of his armed men embarrassed the head of the U.N. Relief and Works Agency, the body that administers Palestinian refugee camps.

Weapons are banned in the camps, but during four years of violence, armed gangs have taken control, building their reputations through deadly attacks on Israelis. The unarmed Palestinian police have been shunted aside.

Zubeidi, West Bank head of the Al Aqsa Martyrs’ Brigades, a violent group linked to the ruling Fatah party, strode to the gate of the compound housing U.N. agency offices, passing signs on a fence showing the silhouette of a gun with a red line through it.

After a brief argument with a guard, he checked in his M-16 assault rifle with telescopic sight and walked in — a pistol clearly visible on his hip.

“Of course I don’t condone it, but it’s a fact of life,” UNRWA head Peter Hansen told The Associated Press, referring to the violation of the no-arms rule. “Look around the camp. We can’t stop it — we don’t have guns.”