Reports in Libya suggest dozens more Egyptians could have been rounded up and kidnapped in areas controlled by jihadist groups Ansar al-Sharia and the Islamic State (Isis).

Local media claims that at least 35 Egyptians, mainly farm workers, have been kidnapped by gunmen belonging to the two Islamist groups.

The Libya Herald reported that the fresh abductions occurred after Egyptian jets bombed IS targets in their Libyan base of Derna following the jihadist group's release of a video showing the beheading of 21 Egyptian Coptic Christians.

The airstrikes, hitting locations and weapons stockpiles belonging to IS in Libya, killed about 50 militants and were conducted in coordination with the internationally-recognised Libyan government, which set up in the city of Tobruk after losing control of Tripoli.

Libyan Dawn, an Islamist-led militia backing the rival government based in Tripoli, called on Egyptians to leave the country in 48 hours in the wake of the strikes.

Omar al-Hassi, premier of the self-declared Tripoli government, condemned the Egyptian-led airstrikes as an attack on the country's sovereignty. He said that three children, two elderly men and a 21-year-old woman were killed in the attack, according to Reuters.

The video released by IS claimed to show the beheading of 21 Egyptian Coptic Christians on a beach in Libya.

Ansar al-Sharia pledged its alliance to IS, which controls large parts of Iraq and Syria, in November last year.

Libya has been in turmoil ever since the removal of Muammar Gaddafi from power. The struggle for power currently includes forces loyal to Khalifa Haftar - a rouge general who has launched a campaign against jihadi groups with the backing of Libya's frail government - two rival governments and several Islamist militias.