Jordan's air defences were ready to intercept and shoot down any Iranian drones or aircraft that violate its airspace, two regional security sources said.
They said the army was also in a state of high alert and radar systems were monitoring any drone activity coming from the direction of Iraq and Syria.
Residents in several cities in the northern part of the country near Syria and central and southern areas heard heavy aerial activity. A security source said the country's air force was intensifying reconnaissance flights.
Jordan had earlier said it closed its airspace starting on Saturday night to all incoming, departing and transiting aircraft in what officials said were precautionary measures in the event of an Iranian strike across its border.
"The relevant authorities took the decision to close the airspace for precautionary reasons as a result of the surrounding security situation," Jordan's government spokesperson Muhannad Mubaideen said.
Mubaideen denied media reports that the kingdom had announced a state of emergency, adding they were baseless and there was no cause for concern among its citizens.
Jordan neighbours Syria and Iraq – both countries where Iranian proxy forces operate – and also is next door to Israel and the Israeli-occupied West Bank.
It has watched Israel’s war against the Palestinian group Hamas, another Iranian ally, with rising alarm for fear of getting caught in a crossfire.
Late last year, Amman asked Washington to deploy Patriot air defence systems to Jordan to bolster its border defences.
Officials say the Pentagon had since increased its military aid to the kingdom, a major regional ally, where hundreds of U.S. troops are based and hold extensive exercises with the army throughout the year.
In January, three US service members were killed and dozens wounded in a drone attack by Iran-backed militants on US troops in northeastern Jordan near the Syrian border.
It was the first deadly strike against US forces since the Israel-Hamas war erupted in October, and marks a major escalation in tensions that have engulfed the Middle East. - Reuters