Jordanian security forces say they engaged “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 Syria and Iraq.
It joined the US and several Gulf Arab states in carrying out air strikes on IS militants in Syria in September 2014 to “ensure the stability and security” of its borders.
The killing of Jordanian pilot Moaz al-Kasasbeh, captured by IS in December 2014, appeared to strengthen the government’s resolve to take on the group.
But 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.
Some officials and local media described the gunmen as “extremists” but it is not clear whether any organised group is behind the incident.