Updated

Two Marines were severely burned Sunday night after a fighter jet exploded while they were conducting routine maintenance at a San Diego air station.

The unidentified Marines were on the tarmac of Marine Corps Air Station Miramar when a "ground flash fire" occurred just after 10 p.m., officials said on Monday. They were performing a routine aircraft maintenance an a F/A-18 at the time.

The Marines were taken to the hospital and treated for severe burns.

The two Marines were part of the Marine Fighter Attack Squadron 112, the reserve unit based out of Fort Worth, Texas.

The incident is under investigation.

Fox News' Jennifer Griffin contributed to this report. 

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