At least four Egyptian embassy personnel have been kidnapped in the Libyan capital Tripoli, the Libyan foreign ministry says.
Another embassy official was seized in the Libyan capital on Friday.
Several kidnappings of officials in Libya recently have been blamed on militias. They are often paid by the government, but their allegiance and who controls them remain in doubt.
On Friday a Libyan militia commander was arrested in Egypt.
Shabaan Hadiya is the leader of the Revolutionaries' Operation Room, one of the militias that sprang up during the fight to topple Libyan leader Muammar Gaddafi in 2011.
Libyan government officials blamed the Operation Room for the brief abduction of Prime Minister Ali Zeidan in October 2013.
Among the Egyptian embassy staff seized overnight was the cultural attache.
An administrative adviser was abducted on Friday. A high-ranking member of the Operation Room denied any involvement in that kidnapping, Reuters news agency reported.
An Egyptian foreign ministry spokesman, Badr Abd-al-Ati, said that the administrative attache had contacted embassy staff in Tripoli to say he was being well-treated, Egypt's Mena news agency reported.
High-profile contacts were underway to free the personnel, the agency added.
Meanwhile, the presidency of the General National Congress, Libya's highest political authority, ordered the ambassador in Cairo to demand an explanation of Shabaan Hadiya's arrest, according to the AFP news agency.