Video footage from earlier in the day showed protesters using umbrellas to try to deflect pepper spray and water cannons as officers attempted to disperse the crowd.
On a return trip to eastern Ukraine, NPR's Eleanor Beardsley found a ceasefire that feels shaky and separatists who are full of swagger and determined to press their fight for independence.
Officials say the hikers were found close to the mountain's peak, in cardiac and respiratory arrest. More than 200 hikers survived Saturday's eruption.
Hong Kong police used tear gas on Sunday as they tried to clear thousands of pro-democracy protesters gathered in a challenge to Beijing over its decision to restrict democratic reforms for the city.
The shooting does not appear to be connected to the protests, police said. The officer, a woman, is expected to recover.