The Egyptian foreign ministry on Monday announced its rejection of foreign intervention in Libya, calling on the neighbouring country's domestic parties to "end divisions and stop bloodshed."
The statement came after the Libyan army decided to impose a no-fly zone last Saturday, a direct challenge to retired general Khalifa Haftar, who has been using airpower to press a campaign against Islamist militants.
On Friday, his paramilitary force, backed by warplanes and helicopters, pounded Islamist militiamen in Libya's second city and fought pitched battles with the ex-rebels.
Prime Minister Abdullah Al-Thani denounced Haftar's forces as "outlaws" and called on all parties to observe restraint.
But Haftar vowed to continue his war against Islamists, blamed for attacks that have killed dozens of members of the security forces, judges and foreigners since the end of the uprising in October 2011.
Haftar, who lived in exile in the United States before returning home to lead ground forces in the 2011 NATO-backed uprising in 2011, heads what he calls a "National Army".
Gunmen stormed parliament in southern Tripoli on Sunday, hot on the heels of an anti-Islamist offensive launched by Haftar in the eastern city of Benghazi.
After the attack on parliament, a colonel claiming to speak on behalf of the National Army declared that the General National Congress (GNC) had been suspended.
Cairo condemned "attempts from inside and outside" Libya to push Egypt into the conflict and regarded the situation as a Libyan internal matter.
The Egyptian-Libyan border is rife with arms smuggling and both countries' have worked together in recent years to limit the activity.
Weapons smuggling out of Libya surged after its 2011 civil war that led to the ouster of long-time dictator Muammar Gaddafi.
With interim authorities failing to build a regular army and police forces, militias have imposed a stronghold over Libya, with large numbers of arms for export freed up.