Six people were arrested in St. Petersburg on suspicion of “aiding terrorist activities,” but there’s no evidence yet that they were linked to the city’s suicide train bomber, Russian authorities said Wednesday.

The suspects, from Central Asian origin, had been recruiting other Central Asian migrants in St. Petersburg to join the ranks of terror groups such as the Islamic State since November 2015, Russia’s Investigative Committee said.

Authorities have said Russian-born Akbarzhon Dzhalilov, 22, who hails from the largely Muslim-populated Central Asian nation of Kyrgyzstan, is the man responsible for carrying out Monday’s deadly bomb blast that killed 14 aboard a crowded train in Russia’s second largest city.

Extremist Islamist literature was discovered during a search of the detainees’ homes, officials said.

The committee noted, “At this moment the investigators have no evidence of connection or acquaintance of the detained with executor of the terrorist action in the St. Petersburg metro.”

Dzhalilov, 22, a sushi-chef-turned-suicide-bomber, was killed in the explosion that also wounded at least 50.

Meanwhile, his parents — who have said they have not seen their son for quite some time — arrived in St. Petersburg on Wednesday for questioning.

A woman believed to be Dzhalilov’s mother reportedly told a Russian TV reporter that she did not believe her son was the bomber.

Investigators scoured the St. Petersburg home of Dzhalilov and reviewed surveillance footage that shows him leaving his home with a bag and a backpack.

Dzhalilov carried a bomb in a backpack that exploded on the train as it was traveling in between two stations, investigators said. He left a second explosive device disguised as a fire extinguisher at another station where authorities later de-activated it.

His DNA was found on the bag, authorities said.

Russian President Vladimir Putin on Wednesday commented on the attack during a meeting in Moscow with security officials from former Soviet countries.

“We see that, unfortunately, the situation is not improving. The recent tragic events in St. Petersburg are the best confirmation of this,” Putin said.

“We know that each of our countries, practically every one, is a possible and potential target of terrorist attacks.”

With Post Wires