Hong Kong Chief Executive Carrie Lam, center, leaves a mosque in Hong Kong, Monday, Oct. 21, 2019. Lam and other officials apologized to leaders of the Kowloon Mosque after riot police sprayed the building's gate and some people nearby with a blue-dyed liquid from a water cannon as they tried to contain pro-democracy demonstrations Sunday. (AP Photo)
People stand at the entrance to the Kowloon Mosque a day after it was sprayed with blue-dyed water by a police riot-control vehicle in Hong Kong, Monday, Oct. 21, 2019. Hong Kong officials apologized to leaders of a mosque after riot police sprayed the building's gate and some people nearby with a water cannon as they tried to contain pro-democracy demonstrations. (AP Photo/Mark Schiefelbein)
Blue stains are seen on the steps of the Kowloon Mosque a day after it was sprayed with blue-dyed water by a police riot-control vehicle in Hong Kong, Monday, Oct. 21, 2019. Hong Kong officials apologized to leaders of a mosque after riot police sprayed the building's gate and some people nearby with a water cannon as they tried to contain pro-democracy demonstrations. (AP Photo/Mark Schiefelbein)
In this Sunday, Oct. 20, 2019 photo, people react after sprayed with blue-dyed water by a police riot-control vehicle during a protest outside the Kowloon Mosque in Hong Kong. Hong Kong officials apologized to leaders of the Kowloon Mosque after riot police sprayed the building's gate and some people nearby with a water cannon as they tried to contain pro-democracy demonstrations. (Chan Cheuk Fai/The Initium via AP)
A lamp outside the mosque is sprayed by blue-dyed liquid in Hong Kong, Sunday, Oct. 20, 2019, after a water cannon truck prayed a stinging blue-dyed liquid as police moved to clear the road of protesters and barricades outside a mosque. Local broadcaster RTHK reported that the people hit were guarding the mosque and few protesters were nearby, and the Hong Kong police force said it was an "unintended impact" of its operation to disperse protesters and later sent a representative to meet the mosque's Imam. (AP Photo/Kin Cheung)
People walk past a mosque next to a subway station at a main road in Hong Kong Sunday, Oct. 20, 2019, Hong Kong. A water cannon truck and armored car led a column of dozens of police vans up and down Nathan Road, a major artery lined with shops, to spray a stinging blue-dyed liquid as police moved to clear the road of protesters and barricades.(AP Photo/Vincent Yu)
Bystanders look at the Kowloon Mosque a day after it was sprayed with blue-dyed water by a police riot-control vehicle in Hong Kong, Monday, Oct. 21, 2019. Hong Kong officials apologized to leaders of a mosque after riot police sprayed the building's gate and some people nearby with a water cannon as they tried to contain pro-democracy demonstrations. (AP Photo/Mark Schiefelbein)
Pedestrians walk past a blue-stained sidewalk outside the Kowloon Mosque a day after it was sprayed with blue-dyed water by a police riot-control vehicle in Hong Kong, Monday, Oct. 21, 2019. Hong Kong officials apologized to leaders of the Kowloon Mosque after riot police sprayed the building's gate and some people nearby with a water cannon as they tried to contain pro-democracy demonstrations. (AP Photo/Mark Schiefelbein)
Police officers using speakers to warn protesters on the street of Yuen Long, Hong Kong, Monday, Oct. 21, 2019. A evening sit-in at a suburban train station on the three-month anniversary of a violent attack there on protesters by men with suspected organized crime ties. (AP Photo/Vincent Yu)
Riot police officer aims his tear gas gun at protesters on the street of Yuen Long, Hong Kong, Monday, Oct. 21, 2019. A evening sit-in at a suburban train station on the three-month anniversary of a violent attack there on protesters by men with suspected organized crime ties. (AP Photo/Mark Schiefelbein)
Riot police clash with protesters on the street of Yuen Long, Hong Kong, Monday, Oct. 21, 2019. A evening sit-in at a suburban train station on the three-month anniversary of a violent attack there on protesters by men with suspected organized crime ties. (AP Photo/Mark Schiefelbein)
Police push back media on the street of Yuen Long, Hong Kong, Monday, Oct. 21, 2019. A evening sit-in at a suburban train station on the three-month anniversary of a violent attack there on protesters by men with suspected organized crime ties. (AP Photo/Mark Schiefelbein)