Brazil has sent heavily armoured military vehicles into a slum in Rio de Janeiro in a major escalation of the government's fight against drug related crime in the city's shantytowns.
Police said on Thursday that drug gang leaders have been seen fleeing the Vila Cruzeiro slum as Brazilian authorities work to "retake" the area.
"At this moment, Vila Cruzeiro belongs to the state," Rodrigo Oliveira, a police spokesman, said.
More than 17,000 police officers have been deployed across the city, and at least 30 suspected drug traffickers have been killed since the operation began on Sunday, police officials said.
Cristiana Sousa, the chief producer for TV Globo, told Al Jazeera that the situation appeared to have calmed down after dark on Thursday.
"It's very rainy. The police are still occupying the shantytown but it's not as violent as it was in the afternoon," she said.
Al Jazeera's Gabriel Elizondo, reporting from just outside Vila Cruzeiro at midnight, said the streets were empty.
"Security officials have said that nobody should be out under any circumstances, because it's simply too dangerous."
Eight people were killed in the push into Vila Cruzeiro on Thursday, as police arrived in the slum under the cover of helicopters. The push came amid the rattle of gunfire despite the gang members' efforts to block access with burning vehicles.
Gang members fleeing
The offensive is part of a police campaign to control crime in Rio's drug gang-ridden slums, known as favelas, in the lead up to the country's hosting of the World Cup in 2014 and the Olympic Games in 2016.
Footage from Brazil's TV Globo showed heavily armed gang members escaping to a neighbouring slum as police neared the shantytown.
|More than 17,000 police officers have been deployed across the city [AFP]
Violence erupted late on Sunday when gang members attacked police stations in northern Rio.
At least 180 people have been detained since then, police said, adding that they had also seized weapons and drugs.
At least 60 vehicles, including nearly a dozen city buses, have been set ablaze since the violence began, they said.
Our correspondent said police figured that the attacks were stemming from Vila Cruzeiro.
"Police have gone into many other favelas over the last several years to 'pacify' them, in their words," he said.
"They felt this was the right opportunity to go into Vila Cruzeiro because their intelligence said that the gang there was responsible for those deadly attacks.
"One of the strongest, most powerful and most dangerous trafficking gangs in Rio has its base there."
The unrest has paralysed a large part of the city, as local television has been dominated by images of buses engulfed in flames and heavily armed police and special forces fighting their way through the slums.
Around two million of Rio's inhabitants - a third of the population - live in more than 1,000 slums.
"Most of the people who live in the favelas are not criminals. Most of them are just average working people," Elizondo said.
"They want security, they want the drug traffickers out of their neighbourhoods. But clearly this is a painful process because the only way to do it is to send in these heavily armed police officers and quite frankly, there's a lot of bullets that start to fly and innocent people get killed."
He said there were reports of four civilians being caught in the crossfire on Thursday, including a 14-year-old girl hit by a stray bullet.
Police said they were battling two factions of drug dealers that have joined forces seeking to disrupt a two-year-old pacification programme aimed at retaking control of the slums from the gangs.