Images and videos said to have been taken at the scene were rapidly spread on social media, showing a huge ball of flame rising into the sky, followed by the sound of several explosions.
Witnesses said huge orange flames lit the desert night sky and could be seen as far away as the capital Amman, which lies 35 kilometers (22 miles) to the southwest.
“We felt like an earthquake had struck. Our windows shook and glass shattered. My kids started crying,” Zarqa resident Nabila Issa, a housewife and mother of five children, said.
Security forces sealed off the sprawling industrial city, and prevented traffic from leaving or entering.
Journalists who wanted to travel through Zarqa to the blast site were also prevented from doing so.
Government spokesman Amjad al-Adaileh said in a statement that “the explosion occurred in the early hours of Friday … in a warehouse containing unusable mortar bombs belonging to the armed forces.”
The statement added that an initial investigation had determined that “the blast was caused by an electrical short circuit in warehouses situated in an isolated and uninhabited area” which was under camera surveillance.
However, an army source said on condition of anonymity that some of the weapons at the site were precision-guided anti-aircraft missiles.
The army later acknowledged in a statement that there had been an explosion “in one of the ammunition depots which is being dismantled near the city of Zarqa.”
It added that “a committee has been set up to determine the causes of the explosion.”
There were no immediate reports of casualties from the explosions.
The desert area where the blasts took place houses several major US-equipped army bases, including an airfield built in 2018.
US officials say that military aid to Jordan helps Washington widen its military activities in the region, including for American troops deployed in the strategic al-Tanf region in southeastern Syria.
Back on August 25, the Russian military said the United States continues to support acts of terror and sabotage by allied Takfiri terrorists operating in Syria’s al-Tanf region to justify its illegal military deployment in the war-torn Arab country.
“Through their actions, the terrorists disrupt the process of socio-economic reconstruction of Syria and the establishment of relations between local Arab tribes and the Damascus government. Such a situation primarily benefits the United States, and allows it to justify its presence in the country’s east,” Russia’s Sputnik news agency quoted an unnamed spokesman for Russian forces in Syria as saying at the time.