German police arrested four people, including a Syrian teenager, accused of planning a terror attack on a synagogue in the western town of Hagen ahead of the Jewish Yom Kippur holidays, local media reported Thursday.

The arrests came in the wake of an unnamed foreign secret service tip-off that an alleged terror attack was imminent, according to the Berlin-based Der Tagesspiegel newspaper.

Police armed with machine guns increased their protection for the Hagen synagogue Wednesday evening and cordoned off the area.

Hagen police said they had also searched several buildings following the arrests.

Meanwhile, the synagogue canceled its religious service due to the terror threat.

Reacting to the investigation, German Justice Minister Christine Lambrecht spoke of a "very serious threat."

The incident awakens horrific memories of the attack on the synagogue in the eastern city of Halle two years ago, said Lambrecht, according to a statement from her ministry.

Lambrecht was referring to a terror attack in which an armed right-wing extremist tried to force his way into the synagogue and shot two nearby people dead.

The 28-year-old man, who confessed to carrying out the attack, was convicted last year and given a life sentence.

- It is unbearable that Jews are again exposed to such a terrible threat and were unable to celebrate the beginning of their highest festival, Yom Kippur, peacefully together - she added.

The German government has been deeply alarmed by a surge in anti-Semitic hate crimes over the past years.

The number of registered anti-Semitic hate crimes in Germany reached a new peak last year, according to figures released by the government, as authorities have reported at least 2,275 crimes with an anti-Semitic background until the end of January 2021, among them 55 acts of violence.