Suspicions of an ISIS involvement in the Saturday blast at the Nanaksar Satsang Sabha Gurudwara, which occurred at the end of a marriage ceremony, have hardened following the arrest of two 16-year-olds in the nearby town of Gelsenkirchen last night.
The two teenagers with known links to regional Islamists have been arrested over the attack which left three persons, including a priest, injured, said city police chief Frank Richter.
"We have to presume it was a terrorist act -- religiously motivated terror by the Islamist scene," Richter said.
"We will continue to do everything possible to ensure the protection of the Sikh community in Essen," Richter said. "Our work does not end with the arrest of the two suspects. There are numerous leads that need to be evaluated."
The strength of the Sikh community members in Germany is estimated around 15,000.
Earlier, one of the two men identified by police as Yusuf T, an ISIS sympathiser, is now treated by investigators as the main suspect in the attack, ARD TV network reported.
He is known to the authorities as an activist in the Islamist scene in the Ruhr region of North Rhine Westphalia and has been actively involved in a campaign to distribute free copies of the Quran in the German-speaking region organised by a radical Salafist sect of Islam.
Yusuf also has links to "Lohberger-Brigade", an alliance of radical Islamists in the town of Dinslaken, the report said.
Most of German Islamists who have travelled to Syria to join ISIS militants had close links to LIES, the organisation behind the Quran distribution campaign, according to the report.
Yusuf had used his Facebook profile to carry out propaganda for the ISIS, it said.
Media reports said earlier that his mask thrown into a bush was recovered by police and it was being subjected to DNA analysis.
Police yesterday released photos and CCTV footage of two men suspected of planting a backpack containing a bomb in the entrance hall of the gurudwara.
One of them carried a backpack with the logo "Russel Athletic". Investigators found the remains of a similar back pack in the debris of the explosion, according to police.
India had expressed "distress" at what has been deemed as a deliberate act from the beginning. Top Indian officials have already taken it up at the highest level as Essen authorities assured India that all steps will be taken to ensure security for all minorities including the Sikhs.
Last Updated 31, Mar 2018, 6:53 PM IST