Venezuelan officials say 22 suspected gang members and four police officers have died in two days of clashes in the capital Caracas.
Interior Minister Carmen Meléndez says an unspecified number of civilians were killed and nearly 40 people injured.
Hundreds of officers have been deployed to search for gang leaders, who have been seeking to expand their territory. One resident said it was “like a war”.
The police have seized weapons, including 24,000 rounds of ammunition.
Images shared on social media showed bullet castings littering the ground in the Cota 905 neighbourhood on Friday.
One officer told AFP news agency that authorities were now in control, but said “there may still be a few snipers”.
Some 800 security personnel were deployed to affected areas, where they conducted house-to-house searches.
Ms Meléndez said police had “advanced in the dismantling of the criminal structures that have settled in these territories with the intention of sowing terror”.
She said the officers had freed citizens kidnapped by the gangs, and would remain deployed “as long as necessary”.
The Venezuelan government has offered rewards of up to $500,000 (£360,000) for information leading to the detention of gang bosses.
Local human rights groups called for a de-escalation in the violence, expressing “deep concern for the lives and safety” of local residents.
While the shooting appears to have died down, dozens of civilians have been fleeing their homes, frightened of being hit by bullets.
“We are experiencing trauma”, one Cota 905 resident told the Associated Press news agency.
The operation marks the first time in years that authorities have launched a major offensive against the gangs, AFP reports.
The government accuses the opposition, with the help of foreign powers, of orchestrating the violence to “destabilise” President Nicolás Maduro.
But opposition media outlets said the government was to blame.
An op-ed published by newspaper El Universal said the powerful El Coqui gang’s firepower had “disproportionately grown while state security bodies that exist to confront them and reduce them, have seen themselves diminish through the years”.
An editorial by El Nacional said the strength of the gang was “a result of [the government] having given these criminals all types of advantages”.
Venezuela has been caught in a downward spiral for years with growing political discontent further fuelled by hyperinflation, power cuts, and shortages of food and medicine.
Critics say basic services, like policing, health care and road maintenance, have been neglected.