Just days before Christmas on this day three years ago, Berlin was hit by a terror attack that claimed the lives of 12 innocent people and shocked the country.

On December 19th, 2016, terrorist Anis Amri, from Tunisia, hijacked a truck, killed its Polish driver and drove the vehicle through the Breitscheidplatz Christmas market, claiming 11 more lives and wounding more than 70 people, some severely.

It led to increased security measures being put in place around the market, including steel pedestals and sand-weighed mesh baskets.

Relatives and friends of those killed and injured, as well as survivors, will gather at the Kaiser Wilhelm Memorial Church, also known as the Gedächtniskirche, on Thursday from 7.30 pm to mark the anniversary, reported local newspaper B.Z.

The victims of the attack were Anna and Georgiy Bagratuni, Sebastian Berlin, Nada Cizmar, Fabrizia Di Lorenzo, Dalia Elyakim, Christoph Herrlich, Klaus Jacob, Angelika Klösters, Dorit Krebs, Lukasz Urban and Peter Völker.

At the memorial at Breitscheidplatz, the names of those who died will be read aloud first. The governing mayor Michael Müller will then lay down a wreath. At 8.02pm – the exact time the truck was driven into the market – the bells of the Gedächtniskirche will strike 12 times for each of the people who died.

On the steps at the front of the the Gedächtniskirche, a metre-long, gold decorated crack engraved into the stone is a memorial to the 12 people who died because of Amri's actions. Their names are engraved around it, as well as the countries they come from.

Amri was shot dead by Italian police while on the run in Milan, four days after the attack, which was claimed by the terror group known as Islamic State (IS).

The truck crashed into the market in 2016. Photo: DPA

There have been concerns over the way authorities handled the Amri case. It emerged that Amri, who arrived in Germany in 2015 and registered under several different identities, should have been deported.

German media also revealed that the Tunisian had been under close surveillance by Germany's secret service but they failed to act in time.

On the third anniversary, Müller called for unity in the face of terror. He said these crimes should not “drive a wedge into our society”.

So far, around €4.3 million in financial aid has been given to those affected and surviving families. At least three people are to receive monthly payments for life.

'Liberal democracy is vulnerable'

President of the Bundestag Wolfgang Schäuble commemorated the victims in a speech.

“These victims have not been forgotten,” he said. “The act left deep wounds, sadness for the bereaved, pain and trauma for the affected and a lasting injury in our society, for we see that liberal democracy is vulnerable.”

Schäuble said the state could not guarantee 100 percent safety for all citizens. “But we are doing everything in Germany to protect the freedom of each individual,” he said.

Anti-terror security measures were put in place at the market. Photo: DPA

The Breitscheidplatz market is one of the most popular in Berlin. The operators expect around a million visitors to the site this year.