Jordanian security forces say they are fighting “outlaws” in the northern city of Irbid.
The state-run Petra news agency said three members of the security forces had been injured. It also said some fighters had been killed and injured.
Early reports say the fighters in Irbid, which is near the Syrian border, may be Islamist militants.
Jordan is part of the coalition acting against so-called Islamic State (IS) in Iraq.
In January, the chief of Israel’s armed forces warned Jordan could become a target of IS attacks.
Heavy gunfire could be heard in videos purportedly from the scene published by local media.