Baghdad ? The U.N. refugee agency said Friday that it was rushing aid to thousands of Christians who fled a northern Iraqi city, while a prominent Shiite cleric appealed for unity as lawmakers consider a U.S.-Iraq security deal.

Some 13,000 Christians have been chased away by threats and extremist attacks in Mosul this month, said Ron Redmond, spokesman for the U.N. High Commissioner for Refugees.

That number is more than half the community in a city where Christians have lived since the religion’s early days.

“Many left with little money and need help,” Redmond told reporters in Geneva, where the agency has its headquarters.