OSLO, June 21 (Xinhua) -- A total of 11 cars in Oslo were most likely deliberately set on fire during the previous two nights, newspaper Afteposten reported Wednesday.
Major police resources are set up to find the perpetrators.
"We look of course very seriously at this. All available units have been in action during the night, including the police helicopter. Measures have already been taken and more measures will eventually be put in place," said Rune Ullsand, operations manager in the Oslo Police District.
The police were firstly notified of two car fires 25 minutes after midnight Wednesday, which followed by a new warning at 2:48 a.m. local time when a total of six cars were caught by fire in Hersleb's street in Oslo's Old Town district.
According to Ullsand, the fire flames from one car were spread to another five cars.
"The investigation continues throughout the day and we may be able to provide more answers later. There have been technical investigations on both sites and we have searched for a white car that a witness saw driving at high speed after the fire at the Furuset area. We have also questioned a lot of witnesses and conducted surveys. We have also received surveillance videos," Ullsand said.
The police could still not confirm whether these fire incidents were connected to the three fires that happened the night before.
Nobody has so far been arrested after Tuesday's car fires, Aftenposten wrote.
"The cases are investigated as single events, but are seen in connection with proximity and that both are car fires. We still do not know if they were deliberately caused, but can not rule it out," said Rune Skjold, section leader in Oslo Police District, on Tuesday.
In addition to many patrols and police helicopters, the police have also put police dogs in search of traces of potential perpetrators in the last two nights.
All the 11 cars on fire were empty.