MALMO, Sweden (Reuters) - After years in the military and police dealing with bombs and mines in ex-Yugoslavia, Lebanon and Iraq, Goran Mansson is now back home advising Swedes what to do if they find an unexploded grenade on their street or in a playground.

Goran Mansson, head of Malmo's bomb squad, displays unexploded grenades found this year in the city August 5, 2015. REUTERS/Elias von Hildebrand

As bomb squad chief in the western port city of Malmo, Mansson has been busy with a dozen grenade attacks in the last few months. They have shocked a Nordic country that prides itself on safety, led to worries criminality is out of control and given political fodder to a resurgent far-right that blames immigrant gangs for the violence.

“It is strange to be doing almost the same in Malmo that I was doing in Iraq,” Mansson said at his headquarters where unexploded grenades - manufactured in ex-Yugoslavia - were neatly lined up on his desk.

The attacks, as well as other bombs placed in cars and parks, have wounded two people this year but not killed anyone. The pattern of targets – from flats to offices and one building housing a Ramadan celebration – appears random. No one has been arrested.

The best guess, experts say, is a gang turf war that could easily see fatalities as tit-for-tat attacks spiral.

Iraqi-born Ghanem Almanei described the attack on the Ramadan celebration, attended by some 50 people. “It was a really big bomb. It was women, girls inside.” said Almanei, his voice shaking, half-an-hour after men on motor bikes threw a grenade against the building. “I don’t feel safe now in this country.”

These incidents have focussed attention on gang-related violence in one of Sweden’s most segregated cities where unemployment rates top 40 percent in some deprived, mainly immigrant areas.

The bomb and grenade attacks – in six months already near the total level of 2014 - came the same year as a mass shooting in the nearby city of Gothenburg. Two masked men opened fire in a bar, killing two and wounding at least 10 people.

“These attacks are creating terror and it plays into the hand of the far right” said Joakim Palmkvist, a Swedish journalist and author of Mafia War. “The general effect is scaring the public to an extent that has been unknown before.”

While most Swedes are open to immigrants, the far right Sweden Democrats became the third biggest party in parliament in last year’s election, in part by demanding a clampdown on immigration and crime.

“This (wave of grenade attacks) is because we have segregation in Sweden and most of it is in Malmo,” said Jorgen Grubb, Sweden Democrats chairman in Malmo. “It’s always people from other countries that do these things. What Malmo needs is to put up a red stop sign.”

But the city’s most infamous killer was Swedish-born - Peter Mangs was arrested in 2010 for three murders and 13 attempted murders over a seven-year period, a string of shootings in Malmo targeting immigrants.

SMUGGLING HUB

With a population of just 300,000, Malmo has long been a smuggling hub due its closeness to Denmark, with which it has been connected by a bridge to Copenhagen since 2000.

Around a third of the city’s population are immigrants - double the national average, and nearly one in three is unemployed. Among young immigrants, the rate is nearly 40 percent - Somalis, Iraqis, Bosnians and Iranians squeezed into concrete tenement blocks.

Gangs began here decades ago as motorcycle groups and were increasingly dominated by immigrants, thanks to an influx in the 1990s of refugees of Balkan wars and then immigrants from the Middle East, Africa and eastern Europe.

It is this mixture of poverty, joblessness and immigrants that has given Malmo a reputation as Sweden’s roughest city – what some newspapers have called Sweden’s “Chicago”.

Most grenades have been smuggled from the Balkans to Malmo, a gateway to the rest of Scandinavia for drugs and arms. The leader of one main gang is said to be a Serbian who came to Sweden as a refugee in the 1990s. Palmkvist says grenades can be bought in the black market for a little as 70 dollars each.

“Terror is not just about a lone gunman,” author Palmkvist said, referring to attacks by a 22-year-old man on a synagogue and free speech event in Copenhagen - a short car ride across a bridge from Malmo - that killed two people in February. “Terror is also about a lot grenades being thrown.”

The city’s main mosque has suffered several arson attacks. Jewish groups have warned of growing anti-Semitic attacks. Two schools were closed this year due to violence among students.

With its street cafes and gentrifying old port, Malmo still seems a picture of Swedish prosperity. In the poorest districts, carefully tended gardens and children’s parks compare favourably with some of Europe’s inner cities.

But that has not stopped a sense of fear in the city.

“I feel very concerned. I have a daughter who is growing up here,” said Kristin Lidgren, who works with a theatre group. “The danger is young people take this way of criminal life as normal.”

With no arrests after the recent attacks, local media have criticised police for being undermanned as officers head to the beach, underscoring what some argue is complacency and resignation on the part of the authorities.

“It’s the summer and many police are on holidays.” said Palmkvist. “Welcome to Sweden.”