Anti-World Cup protests in 12 cities have marked the worst day in another awful week for Brazil as the government struggles with strikes, crime and public unease less than a month before the tournament kicks off.

Co-ordinated demonstrations in Rio de Janeiro, São Paulo, Belo Horizonte and elsewhere coincided with a military police strike – and spate of murders – in another World Cup host city, Recife, to add to the organisers' headaches as hundreds of thousands of players, fans and officials prepare to fly into the country.

The events follow industrial action in Rio earlier in the week by teachers, bus drivers, museum employees and geologists, and underline longer term concerns about public safety and transport infrastructure.

The protest of about a thousand people in Rio was far smaller than the huge demonstrations seen last year but adds to an unusual muted and emotionally complicated atmosphere in Brazil as it prepares to host its first World Cup since 1950.

Carrying banners declaring “Na Copa vai ter luta” (The Cup will have protests), appeals for a general strike and claims that the cost of refurbishing the Maracanã stadium could pay for 200 schools, the demonstrators rallied with striking workers in the broadest show of dissent in several months.

Many of those present cited the proximity of the tournament and the global media attention it brings as a driver for their actions.

“The world is looking to Brazil and we are showing that the World Cup doesn’t represent us,” said Felipe Mesquita, a history student at the Fluminense Federal University. “I like football. I like the national team but we also have to think about what the World Cup means. We shouldn’t accept all the bad things that go with it such as forced relocations and the limits on rights to protest and strike.”

In São Paulo police used tear gas and rubber bullets against demonstrators. In Belo Horizonte about 2,000 people took to the streets. In Brasilia protesters carried banners decrying the deaths of stadium workers in the rush to finish before the tournament.

Brazil has also been hit by a wave of strikes in recent weeks. Teachers in Rio have halted classes for several days to call for better pay and working conditions. They were joined on Thursday by bus drivers, who had refused to work on Tuesday and Wednesday.

“The World Cup gives us more visibility,” said one striking teacher, Jorge Luiz Monteiro. “We’d like to take advantage of it to find others who will unite with us to fight for better conditions.”

Of greater concern was a continuing strike by military police in Recife – one of Brazil’s most violent cities – which prompted many to take the day off and stay at home. Their security concerns appear to have been at least partly justified, according to reports of a spate of robberies, looting and more than two dozen killings in a day. To allay their fears the local authorities dispatched tanks and armoured personnel carriers through the streets and cancelled two football matches scheduled for the weekend.

Facebook Twitter Pinterest Army soldiers patrol a street during a police strike in Recife. Photograph: Reuters

"They are obviously using the proximity of the World Cup to pressure us to give into their demands," Pernambuco state press officer Manoel Guimaraes told reporters.

While many Brazilians are looking forward to the tournament and eager to see the home team – one of the favourites – take on visiting nations, many observers say the mood is more muted than at the same stage before previous World Cups.

In past years many neighbourhoods joined in competitions to produce street art in support of the national team. But relatively few communities have painted the roads green and yellow or festooned the streets with bunting.

There is still time for this to happen but the low-key response so far has been blamed on the concerns of over-spending, corruption and elitism that are reflected in the protests.

Zico, one of Brazil’s greatest former players, summed up the mood in a column for the Guardian:

While previously World Cup fever would be there for all to see, the atmosphere now is much more subdued. I haven't seen the bunting and painted streets that you might expect to be part of preparations here. To me, it looks like the protests might have put some fans on the back foot, but with a month to go before the tournament starts I wish I could see a bit more joy among the people.

His observations were echoed by the former captain of the Seleção, Carlos Alberto, but he was optimistic that the national mood would change. “There exists a sort of anti-World Cup sentiment and because of this I think people aren’t decorating the streets and wearing the national team shirts as in the past,” he told the Guardian. “But closer to the tournament I think people will come around and they’ll start to get excited. Many Brazilians are currently against the cup, but when the event actually starts all the happiness that comes with Brazilian football will reveal itself and the mood will change.”

The demonstrators had a very different view. “Who would have ever imagined that so many people in Brazil would protests this close to the World Cup,” said Tomas Ramos of Ocupa Copa (Occupy the Cup) movement. “When the World Cup was held in other countries Brazilians traditionally painted the street in green and yellow. But this is not happening any more. Now we want people to paint the street critically. So far the protests have not been very big but we expect them to get huge.”