Updated

German Chancellor Angela Merkel and French President Francois Hollande have paid tribute to the victims of a truck attack on a Christmas market in Berlin a month ago.

The two leaders placed flowers Friday at a makeshift memorial on the capital's Breitscheidplatz where a Tunisian man whose asylum application had been rejected drove a hijacked truck into the market, killing 12 and wounding dozens of others.

The Islamic State group claimed responsibility for the attack.

At a joint press conference ahead of visiting the site, Merkel and Hollande said Islamic extremism was a problem for all of Europe, and vowed to work together to fight it.