Five people were murdered in Stockholm, Sweden, over the past week—and seven were slain since the beginning of the year, indicating a recent spike in violent crime in Sweden's capital city. The murders were the product of at least 12 ongoing gang conflicts in the nation's capital, authorities said.

"We have had a large number of serious crimes and shootings in Stockholm recently. In the past few days we've had five murders in Stockholm. Of course it is alarming and very serious," regional police chief Ulf Johansson said at press conference Thursday. 

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Two men died from gunshot wounds to the head after they were found in a car parked in front of a school Wednesday night in the Swedish suburb of Kista, local media reported. Local TV station SVT said that a witness reported seeing a car drive away from the scene at high speeds. One of the victims was a 26-year-old leader of a local gang. The other victim, a 20-year-old, was a convicted drug dealer, reported Dagens Nyheter, a national daily newspaper in Sweden. Armed officers were deployed to the scene and police conducted door-to-door interviews to collect data, SVT said. 

Patrick Ungsäter, a senior police officer representing the Northern Stockholm area, said the public should not be concerned for their safety, The Local reported

"We see them as isolated gang environments," Ungsäter said.

But just a day before, a middle-aged married couple was brutally murdered in Hallonbergen, another Stockholm suburb just a few miles west of Kista. Police arrived at the scene while the crime was ongoing and arrested three people, a 20-year-old, a 16-year-old and a 21-year-old, Dagens Nyheter reported. 

Murders in Sweden, a country of roughly 10 million people, are relatively rare. The country had 112 cases of lethal violence in 2015, up from 87 in 2014 and 68 in 2012, according to the Swedish National Council for Crime Prevention. In contrast, the U.S. had 15,696 murders in 2015 in a population roughly 32 times larger than Sweden's.