A Russian official said on Wednesday that 33 of the 224 people killed in the Metrojet disaster on Saturday have been identified.

The plane crashed shortly after taking off from the restive Sinai Peninsula for St Petersburg. Everyone on board was killed.

Authorities have not yet determined the cause of the crash. Emergency Situations Minister Vladimir Puchkov said investigators had expanded the search area in Egypt from 30 square kilometers (18.6 miles) to 40.

Shortly after the crash, a group affiliated with the "Islamic State" (IS) terrorist group claimed responsibility, though Russian, Egyptian and American officials have cast doubt on the possibility of the plane having been destroyed by a missile launched from the ground. IS repeated the claim that they were responsible for the attack on Wednesday.

More violence in Sinai

Also on Wednesday, Egyptian officials said at least eight people were dead after a suicide attacker detonated a car bomb at the front gate of a police club.

IS later claimed responsibility for the attack, which also injured at least nine people, including civilians.

Egypt has faced a mounting insurrection from Islamic extremists in Sinai since the fall of President Hosni Mubarak in 2011. On Wednesday, current President Abdel-Fattah el-Sissi said during a trip to Britain that security needed to be tightened in the wake of recent violence, AFP news agency reported.

blc/kms (AFP, AP, dpa)