At least one Syrian refugee has been reported killed in Jordan's sprawling Zaatari camp when hundreds of refugees clashed with security forces, residents said.
They said scores were injured on Saturday as anti-riot police used tear gas to disperse stone-throwing refugees who set fire to official offices and caravans.
Jordanian police blamed agitators who were arrested after trying to flee the refugee camp of nearly 70,000 residents.
Witnesses told the AFP news agency that a Syrian woman was killed. Jordan's Public Security Directorate denied the report.
"Dozens of Syrian refugees at the Zaatari refugee camp rioted after police detained a group of refugees after leaving the camp illegally," the directorate said.
"Twenty-two policemen were injured in the clashes. The rioters burned six tents and two caravans and tried to attack police stations."
Residents say the rioting, the first such serious disturbance this year, was provoked when four-year old Syrian child was knocked over by a Jordanian security car, prompting outrage by residents and relatives protesting against ill treatment.
The camp witnessed almost daily protests over living conditions when it was first set up nearly two years ago but protests have since dwindled as UN agencies stepped up improvements in its infrastructure and services.
The UN says 2.5 million Syria refugees have registered in total, more than 10 percent of Syria's population.
Jordan hosts at least 600,000 refugees with the rest mainly in Lebanon and Turkey.