Mayor of Gdansk Pawel Adamowicz meets Imam Hani Hraish on Monday. Photo: PAP/Adam Warzawa
On Monday morning, RMF FM radio claimed that a source at the prosecutor's office said that a detonation device was found at the site.
However, locals prosecutors have denied this, saying that the case is still being treated as arson.
No arrests have been made to date for the alleged attack.
Animal rights activists are among the suspects in the investigation.
The blaze occurred at about 4 am on Wednesday morning, less than 24 hours after Poland's Chief Mufti apparently defied a state-imposed ban on slaughtering livestock without prior stunning.
Chief Mufti Tomasz Miskiewicz carried out the 'ritual slaughter' in Bohoniki in the Podlasie region of north east Poland, marking Eid-al-Adha, the Feast of the Sacrifice, one of the two most important religious observances for Muslims.
The village has been inhabited for centuries by members of Poland's small Tatar community.
“I am 100 percent certain that this arson was an act of revenge for what happened yesterday in Podlasie,” Gdansk Imam Hani Hraish said just hours after the blaze.
Meanwhile, Mayor of Gdansk Pawel Adamowicz met with Imam Hani Hraish on Monday, and the former appealed to the people of Gdansk to help fund repairs at the mosque.
“The moment has come for solidarity with our Muslim brothers and sisters,” the mayor said.
“Gdansk always was, is and will be an open, tolerant city that is respectful towards all people, regardless of their faith,” he added.
Slaughter of animals without prior stunning was made illegal from 1 January 2013, after animal rights activists lobbied for the matter to be taken to Poland's Constitutional Court.
In July, MPs voted down a draft amendment to the law on animal protection that would have allowed for the slaughter of animals without prior stunning, if carried out so as to follow religious customs.
Prime Minister Donald Tusk supported the amendment, and Minister of Administration and Digitalisation Michal Boni has encouraged Poland's Muslim community to file a complaint with the Constitutional Court. Poland's Union of Jewish Religious Communities has already done so. (nh/pg)
Source: PAP