Angry parents have protested outside the town hall in Ukraine's port city of Odessa over the deaths of two children in a fire at a children's camp.
The remains of a third person were later discovered, though it is not yet known if this was a child or an adult.
PM Volodymyr Groysman called it a "tragedy" saying those responsible would face tough punishment.
On the shores of the Black Sea, the camp is used by authorities to offer underprivileged children holidays.
Footage posted by local journalists on social media showed an angry crowd - parents of the children and local activists - gathered outside the town hall in Odessa on Saturday.
One video showed a group of people running away from the building, many of them coughing. According to Dumskaya website (in Russian), police used tear gas to disperse the crowd.
The news site said they had been trying to confront the mayor.
The blaze broke out overnight inside a wooden two-storey dormitory at Victoria holiday camp, while children were sleeping inside.
Once firefighters managed to extinguish the fire, they discovered three girls aged from 8-12 were missing.
Emergency services said "fragments of two burned children's bodies were found" as debris was cleared.
The remains of a third person were later discovered, but they have not been confirmed as belonging to the third missing child.
Two other children were hospitalised.
Police have opened a criminal case into the fire, while the regional authorities declared a day of mourning.
The director of the camp has been held by police, suspected of violating fire safety procedures.