In a letter to the German Ambassador, party secretary for political affairs, Kanwar Pal Singh said that at a time when Sikhs were "at the receiving end of hate crimes across the globe, the unfortunate incident has further disturbed the community."
At least three persons, including a priest, were injured in the "violent" explosion at a gurudwara in Essen on Saturday.
"The Sikh population in Punjab and elsewhere are worried as this act has created a climate of fear among the diaspora", he said.