Warplanes carried out three air strikes on the Libyan city of Derna on Monday, a witness said, days after Egypt launched strikes on militant camps there against those it said were responsible for killing Egyptian Christians.

On Friday, Egyptian fighter jets struck Derna just hours after masked militants boarded vehicles en route to a monastery and opened fire at close range in the southern Egyptian province of Minya, killing 29 and wounding 24.

No military immediately confirmed Monday's strikes. The witness said one attack hit the western entrance to Derna and the other two hit Dahr al-Hamar in the south.

Islamic State claimed responsibility for Friday's attack in Egypt, the latest targeting Christian minority there following two church bombings last month that killed more than 45, also claimed by the group.

Derna has a history of Islamist militancy and Islamic State first tried to set up its presence in Libya in 2014, but the jihadist group was later chased out by local fighters and rival Islamists with strong roots in the city.