“Just because we have lost our homes, they think our women are free for the taking,” refugee Ibrahim Naimi, 42, said this week as he arranged water pipes in his makeshift cafe at the camp, home to 42,000 Syrians. “We are going to prove that you cannot buy Syrian women.”

Refugees and relief officials said increasing numbers of Arab men and matchmakers have made their way to the camp, some of them posing as aid workers. They say the problem is growing along with the camp, near the northern Jordanian city of Mafraq, in part because many refugee families are impoverished and desperate.

United Nations officials said that most of the marriages are brokered and that many are not consensual. The results, they said, include increasing numbers of child brides and marriages that, in some cases, end in abandonment or forced prostitution. U.N. and Jordanian relief agencies estimate that some 500 underage Syrians have been wed this year.