Carrie Lam, Hong Kong’s chief executive, and the city’s head of police visited Kowloon mosque on Monday to express regret to the chief imam and other community figures.
Although the officials left without commenting publicly, the mosque’s leaders told reporters they had received an apology during the meeting.
“Our mosque is not damaged, nothing is done wrong. Only thing is that they should have not done it. For that they apologised so we accept it," said Saeed Uddin, the honorary secretary of the Islamic Community Fund of Hong Kong.
Police also expressed regret at a press briefing on Monday amid ongoing anger at alleged misconduct during months of protests in the semi-autonomous Chinese territory.
“To any people or any groups that were affected, we offer our genuine apologies,” said Cheuk Hau-yip, the Kowloon West regional commander.
He insisted officers did not have “malicious intent”.
A video filmed by Hong Kong politician Jeremy Tam showed a police water cannon truck spraying the blue liquid at a handful of people standing in front of the mosque’s gate on Sunday. The liquid, used to identify protesters, was reported to be water containing a blue dye and a painful pepper solution
The mosque’s front steps and metal gate and the adjoining pavement were stained with the liquid, while people hit by the solution were left gagging and coughing, according to the video.
Mr Tam said he and two other people, an Indian businessman and the head of a charity for ethnic minorities, went to hospital for checks following the incident.
Volunteers reportedly later arrived to help clean the mosque and by Monday morning the blue stains was largely gone.
The Muslim Council of Hong Kong said it understood the mosque was not targeted by police.
“The police gave prior notice as it approached the area before the use of coloured water. The police then used blue water to disperse people outside the mosque, leaving the gates of the mosque stained,” the council added in a statement.
“It has undoubtedly stirred feelings amongst the Muslim and non-Muslims community in Hong Kong but let us not make the situation worse.”
Hong Kong protesters have seized on the incident as the latest example of overly aggressive police tactics. The pro-democracy movement has called for broader political rights and police accountability in the city, which has seen unrest and major demonstrations since early June.
Police have accused protesters of being “rioters” and arrested 68 people over the weekend.
They said demonstrators hurled more than 100 fire bombs and damaged more than 100 sets of traffic lights.
Hong Kong is home to more than 300,000 Muslims, according to the Islamic Community Fund, which runs the city’s five mosques and two Muslim cemeteries.
The treatment of Muslims in China has come under scrutiny in recent years due to alleged human rights abuse of Uighurs and other Muslim ethnic minority groups.
Additional reporting by agencies