German police have detained an Algerian man who allegedly warned Syrian asylum seekers last week of an imminent attack in Paris.

Witnesses said the man, who was detained at an asylum seeker shelter in the town of Arnsberg in central-west Germany, told Syrian asylum seekers that “fear and terror” would be spread in the French capital.

He is also alleged to have spoken about a bomb.

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The senior public prosecutor in Arnsberg, Werner Wolff, said checks were being made into whether the allegations were credible.

“There is currently an investigation into whether the man is an accomplice or a confidant,” said Ralf Jaeger, interior minister for the state of North Rhine-Westphalia (NRW).

Mr Jaeger added that there was no solid evidence at the moment that the attackers in Paris had a connection to the region.

“There is also no concrete evidence that attacks are planned in NRW or the [German] federal republic,” he said, adding that the situation was nonetheless “very serious”.

Authorities had their eyes on some Salafi Islamists and German jihadists who had been in Syria and Iraq, Mr Jaeger said.

“Fifty who have returned are known,” he added.

Friday evening’s coordinated suicide bombings and shootings in Paris left 129 people dead.

French investigators have named Abdelhamid Abaaoud, a 27-year-old Belgian man who is now believed to be in Syria, as the suspected mastermind of the attacks.