COPENHAGEN, Denmark (AP) — Swedish Prime Minister Stefan Lofven is lashing out at those who set fire to dozens of cars in southwest Sweden, asking them "what the heck are you doing?"

Masked youths torched dozens of cars overnight in Sweden and threw rocks at police, prompting an angry response from the prime minister, who called it "extremely organized" vandalism.

A police spokesman, Hans Lippens, said Tuesday that initial reports indicated that about 80 cars were set ablaze overnight, chiefly in Sweden's second-largest city, Gothenburg.

Swedish Prime Minister Stefan Lofven lashed out at those who set fire to dozens of cars in southwest Sweden, asking them, "What the heck are you doing?"

COPENHAGEN, Denmark — Masked youths torched dozens of cars overnight in Sweden and threw rocks at police, prompting an angry response from the prime minister, who denounced an "extremely organized" night of vandalism.

A police spokesman, Hans Lippens, said Tuesday that initial reports indicated that about 80 cars were set ablaze overnight, chiefly in Sweden's second-largest city, Gothenburg, and nearby Trollhattan, an industrial city.

Fires were also reported on a smaller scale in Malmo, Sweden's third-largest city.

Lippens added that because the fires started within a short period, "we cannot exclude that there is a connection between the blazes."

Swedish Prime Minister Stefan Lofven lashed out at those who set fire to dozens of cars in southwest Sweden, asking them, "What the heck are you doing?"

Lofven said in a Swedish radio interview that he was "really getting mad," adding that "the society must react in a tough manner."

Photos posted by the Swedish newspaper Aftonbladet showed black-clad men torching cars on a parking lot near Gothenburg.

Sweden's news agency, TT, said witnesses saw "masked youngsters" running away. No arrests have been made.

Lippens said several young people who police met at the scene had been identified.

"We have spoken with them but we cannot conclude they started the fires. We also have spoken with their parents," Lippens told local media. He was not available for further comment.

No injuries have been reported. But the fires have occupied police and rescue officials and frightened residents.

"You damage residential areas and ruin it for your neighbors," Lofven said.

Jonas Ransgaard, a member of Gothenburg's city council, told the local newspaper Goteborgs-Posten: "I am speechless. This so terrible, it's destructive, and it's pure evil."