Gang suspected in kidnapping of missionaries is among the country’s most dangerous.

The gang that the police say kidnapped 17 missionaries and their family members in Haiti on Saturday is among the country’s most dangerous and one of the first to engage in mass kidnappings.

The gang, known as “400 Mawozo,” controls the area that the missionaries were abducted from in the suburbs of Port-au-Prince, the capital. The group has sown terror for several months in the suburbs, engaging in armed combat with rival gangs and perpetrating the kidnapping of businessmen and police officers.

The gang has also introduced a new type of kidnapping in Haiti — kidnapping en masse. For the first time year Haiti began to see entire groups kidnapped while transiting on buses or together on the streets. The gang is also believed to have killed Anderson Belony, a famous sculptor, on Tuesday, according to local news media reports. Mr. Belony had worked to improve his impoverished community.

Croix-des-Bouquets, one of the suburbs now under control by the gang, has become a near ghost town, with many residents fleeing the day-to-day violence. The once bustling area now lacks the poor street vendors who once lined the sidewalks, some of whom had been kidnapped by the gang for what little they had in their pockets or told to sell what few possessions they have at home, including radios or refrigerators, to pay off the ransom. By some estimates, gangs now control about half the capital.

With every new generation of gangs that crop up in Haiti, new lows inch further toward normalization. Gangs have plagued Port-au-Prince over the past two decades, but were often used for political means — such as voter suppression — by powerful politicians. But they have grown into a force that is now seemingly uncontrollable, thriving in the economic malaise and desperation that deepens every year, with independent gangs mushrooming across the capital.

While older, more established gangs trafficked in kidnapping or carrying out the will of their political patrons, newer gangs like “400 Mawozo” are raping women and recruiting children, forcing the youth in their neighborhood to beat up those they captured, training up a newer, more violent generation of members. Churches, once untouchable, are now a frequent target with priests kidnapped mid-sermon.

Locals are fed up with the violence, which prevents them from making a livelihood and prevents their children from attending school. Locals started a petition in recent days to protest the rising gang violence in the region, pointing to the 400 Mawozo gang and calling on the police to take action. The transportation industry has announced a general strike beginning Monday in Port-au-Prince to protest the gangs and insecurity.

“The violence suffered by the families has reached a new level in the horror,” the text of the petition reads. “Heavily armed bandits are no longer satisfied with current abuses, racketeering, threats and kidnappings for ransom. At the present time, criminals break into village homes at night, attack families and rape women.”

In April, the “400 Mawozo” gang abducted 10 people in Croix-des-Bouquets, including seven Catholic clergy members, five of them Haitian and two French. The entire group was eventually released by late April. The kidnappers had demanded a $1 million ransom, but it remains unclear if it had been paid.

That kidnapping in Croix-des-Bouquets, a town northeast of the capital, happened when the group was on its way to the installation of a new parish priest.

Michel Briand, a French priest living in Haiti who was part of the group, said the gang had forced their cars to divert from their course before kidnapping them. “If we hadn’t obeyed them — that’s what they told us afterward — they would have shot us,” he said.

The group was then kept by armed men for about 20 days, sleeping on the ground and sometimes out in the open.

“For several months, this group has been acting daily,” Mr. Briand said, adding that the group sought a ransom “to buy weapons and ammunition.”

Mr. Briand said the gang exerted violent control over the area surrounding Croix-des-Bouquets.

“The population complies with their demands because they are armed,” he said. “They have the right to life and death no matter who they meet. They sow terror to ensure their authority,” he said.

Armed groups have become increasingly powerful in Haiti, playing on the political instability and the growing poverty to seize control of large areas of big cities like Port-au-Prince.

“For some time now, we have been witnessing the descent into hell of Haitian society,” said a statement from the archdiocese of Port-au-Prince, released after the April abduction.

A recent upsurge in clashes between rival gangs has resulted in numerous casualties among civilians and extraordinary levels of displacement of people fleeing violence.

A report by the United Nations Office for the Coordination of Humanitarian Affairs estimated that more than 13,600 people had fled their homes in Port-au-Prince, which has a population of nearly six million, in the first three weeks of June. That was four times more violence-related displacement in the capital than in the previous nine months, the report said.