Egyptian polling centers in nearly half of the country, including in the capital of Cairo, have opened their doors to voters for the final round of runoffs in parliament elections.

The balloting is for Egypt's first legislature since a chamber dominated by Islamists was dissolved by a court ruling in 2012. Tens of thousands of troops and policemen have been deployed to safeguard the two-day vote, which started on Tuesday.

The measures reflect growing security concerns amid an Islamic insurgency and after a suspected explosive device downed a Russian airliner over Egypt's Sinai Peninsula in late October, killing all 224 people on board. An Islamic State affiliate claimed responsibility for that attack.

Results will be announced later this week and parliament is to hold its inaugural session later in December.