information leading to their arrests.
A 60-year-old Sikh priest was among three persons who were injured when the bomb went off in the entrance hall of the Gurdwara Nanaksar at the end of a wedding ceremony on Saturday.
Investigators have found the remains of a backpack in the debris of the blast. CCTV camera footage of the two men showed that one of them carried a similar backpack with the logo "Russel Athletic".
The police on Wednesday published photos and video sequences of the two men and asked the public for their help to track them down.
Meanwhile, the state prosecutor's office in Essen has announced a reward of 5,000 euros for information leading to the arrests of the two men.
Two men were arrested from Essen and the nearby town of Bochum on Wednesday but were set free after questioning as the suspicion against them could not be substantiated, media reports said.
They had very little resemblance to the two suspects.
The police is now in possession of new photos showing the faces of the two men more clearly and this could make it easier for the investigators to identify them, the reports said.
The priest, who was seriously wounded in the attack, is now recovering from his injuries at a local hospital.
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