The official Facebook page of Egypt's military spokesman published a video showing warplanes taking off on the mission.
The military said in a statement that it had acted on "intelligence indicating a number of criminal elements had gathered to cross the border into Egypt using a number of four-wheel-drive vehicles".
An official in the armed forces told AFP the vehicles had been on the move from Libya.
Air force units found "the hostile targets, confirmed their coordinates and dealt with them for more than 12 hours," the military said, without specifying when the raids were carried out.
"The operation led to the targeting and destruction of 12 four-wheel-drive vehicles carrying quantities of weapons, ammunition, and explosive materials," it added.
The official Facebook page of Egypt's military spokesman published a video showing warplanes taking off on the mission, as well as footage from the air of vehicles being struck.
Libya has been wracked by chaos since the 2011 uprising that toppled and killed longtime dictator Moamer Kadhafi, with rival authorities and militias battling for control of the oil-rich country.
Egypt has repeatedly expressed concern over militants crossing into its territory from Libya to conduct attacks.
In a speech last month, Egyptian President Abdel Fattah al-Sisi said setbacks by the Islamic State group in Syria were driving its fighters to try to relocate to Libya and Egypt's Sinai Peninsula.
Last month, Egypt launched air strikes against "terror camps" in Libya in retaliation for a deadly attack on Coptic Christians in Egypt, saying the assailants had been trained there.