Three car bombs ripped through the eastern Libyan city of Qubbah on Friday, killing 40 people and wounding 70, security officials and medics said.

There was no immediate claim of responsibility, but parliamentary speaker Aguila Saleh said the bombs appeared to have been in retaliation for Egyptian air strikes on nearby Derna, a militant hotspot.

On Monday, Egypt launched air strikes on suspected Islamic State targets in Derna, a day after the group released a video showing the execution of Egyptian Coptic Christian workers.

Three bombs exploded on Friday at a petrol station, the local security headquarters and the town council headquarters in Qubbah.

"We are announcing seven days of mourning for the victims of Qubbah," Mr. Saleh told Al Arabiya television. "I think this operation was revenge for what happened in Derna."