The fight to succeed popular, long-serving chancellor Angela Merkel could barely be tighter as Germans vote in parliamentary elections.

The streets of Berlin are hosting the annual marathon, but the biggest race is taking place across the country.

In a final push for votes, the outgoing chancellor joined conservative candidate Armin Laschet at a rally on Saturday in his hometown of Aachen.

Final opinion polls suggest an unlikely victory could be within their grasp.

At stake is the leadership of Europe's most powerful economy, and more than 60 million Germans over 18 are eligible to vote.

Polls opened at 08:00 local time (06:00 GMT) on Sunday. A clear indication will come when voting comes to an end at 18:00.