Another source quoted by the official Petra news agency said four "outlaws" and a Jordanian captain were killed.
Two service members and two civilians were also wounded during the operation, the source said, adding that one person had been arrested.
Irbid in a few kilometres from the Syrian border where Jordanian security forces regularly detain drug traffickers and jihadists attempting to join extremist groups in Syria.
Jordan is part of a US-led military coalition that has been carrying out air strikes against IS in Syria and Iraq.
The resource-poor country hosts more than 630,000 of the roughly 4.6 million Syrian refugees overseas, according to the UN refugee agency.
The Jordanian government gives a much higher estimate of 1.4 million, saying many of them are unregistered.
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Two service members and two civilians were also wounded during the operation, the source said, adding that one person had been arrested.
Irbid in a few kilometres from the Syrian border where Jordanian security forces regularly detain drug traffickers and jihadists attempting to join extremist groups in Syria.
Jordan is part of a US-led military coalition that has been carrying out air strikes against IS in Syria and Iraq.
The resource-poor country hosts more than 630,000 of the roughly 4.6 million Syrian refugees overseas, according to the UN refugee agency.
The Jordanian government gives a much higher estimate of 1.4 million, saying many of them are unregistered.
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