Police averted a possible Islamist attack on a synagogue in western Germany and arrested four people including a 16-year-old Syrian youth in connection with the threat, the regional interior minister said on Thursday.
Authorities had received a "a very serious and concrete tip" that an attack on the synagogue in the town of Hagen could take place during the Jewish festival of Yom Kippur, the minister, Herbert Reul, said.
Officers tightened security around the building on Wednesday evening and searched it for bombs but found nothing dangerous, Reul, interior minister for the state of North Rhine-Westphalia, told a news conference.
He said the synagogue had called off its celebration of Yom Kippur, when observant Jews hold overnight vigils. The tip-off had included details of the timing of an attack, he added.
Earlier on Thursday, police in Hagen said they had arrested four people as a result of their investigation into the threat and had searched various buildings.
Reul said one of those detained was a 16-year-old from Hagen with Syrian roots.
Terrorism authorities are involved in the investigation, prosecutors in Dusseldorf said.