Rescue services were alerted of the fire at 04:31. The fire consumed about 10 square meters of the two-story building's exterior sheathing.

Head of Rakvere Police Department Indrek Link said that although no one was hurt, this was a very serious incident. "There were over 50 people in the building when the fire was ignited, 13 of whom were children," he said. "The consequences could have been much more severe."

Police asks anyone who has information on the case to call +372 32 22 674 or +372 51 964 661.

Arson carries a penalty of a fine or up to five year in prison in Estonia.

"It's a grave offense to set the home of 70 on fire in the middle of the night, and needs to be taken as such," Estonia's MEP Urmas Paet told Delfi. "We're dealing with a potential mass murder here. Police and prosecution must do all in their power to find the arsonist(s)," he added.

"For over 20 years we have tried to build a humane society in Estonia and an image of a welcoming country. Actions like last night's put all that in danger," Paet said.

President: all parties must take a stand

"I'm ashamed and embarrassed to read about the fire at the refugee center in Vao, which at the time housed over 50 people, including 13 children," President Toomas Hendrik Ilves said in a statement.

"I expect every parliamentary party to take a public and official stand, from which our citizens can understand who values the rule of law, human life and the constitution," he said.

ERR asked all parties for a comment.

While most party representatives condemned the attack on the refugee center, Martin Helme of the Conservative People's Party (EKRE) said this is just the beginning.

Helme said if mass immigration starts, this was just start. "We've seen it in Sweden and in Germany - people will resist," Helme said. He added: "You shouldn't use mass immigration to destabilize the society. The society will turn violent and such incidents will become endemic. These are just the early birds."

"I think Estonian society should look in the mirror," Free Party chairman Andres Herkel said. "Racist attitudes that surround the whole refugee debate are a matter of fact in our society. And this particular case is appalling. I hope we find out whether it's stupidity, provocation or something else that underlies it."

IRL and Social Democrats faction heads also condemned the incident, as did Prime Minister Taavi Rõivas. Rõivas said there is no justification for the attack and acknowledged the rescue services for their good work.

Mailis Reps of the Center Party agreed that there were warning signs that something like this might happened, but added that everyone must do their best to stop violence from spreading.