CNN  — 

One of Haiti’s most powerful gangs is believed to be behind the kidnapping of 17 American and Canadian missionaries over the weekend, a source in the Caribbean country’s security forces told CNN.

Authorities believe the “400 Mawozo” gang abducted the group, which included 16 Americans and 1 Canadian, after the missionaries visited an orphanage on Saturday in Croix des Bouquets, a suburb northeast of the Haitian capital, Port-au-Prince.

As they were traveling from the orphanage towards Titanyen, north of Port-au-Prince, gang members stopped the vehicle at gunpoint.

The 400 Mawozo gang has been growing in strength for the past three years, numbering up to 150 members, and has essentially taken control of Croix des Bouquets, the source in Haiti’s security forces told CNN on Sunday,

Kidnapping for ransom is a hallmark activity of the gang. They have abducted dozens of people this year alone, including foreign nationals, the source said.

Once notorious for car theft, the 400 Mawozo has pioneered “collective” kidnappings of large groups of victims from buses and cars, according to the Center for Analysis and Research for Human Rights (CARDH), a Port-au-Prince-based nonprofit.

A goat stands in the courtyard of the Maison La Providence de Dieu orphanage in Croix-des-Bouquets, Haiti, on October 17.

Much of the rise in kidnappings in Haiti is due to the 400 Mawozo, according to CARDH. Gang members engage in near daily confrontations with Haitian police and even tax local businesses.

In September, the gang kidnapped “several” truck drivers from the Dominican Republic, and continue to hold them hostage amid negotiations for their release, the Haitian security force source said.

Those ongoing negotiations are factoring into authorities’ decisions about how to proceed with the kidnapped American and Canadian missionaries, the source added.

According to CARDH, the majority of the gang’s victims are Haitian citizens and kidnappings have surged in Haiti this year – with a nearly 300% increase since July.

At least 628 kidnappings have taken place since January, including of 29 foreigners, according to data released by the center. The 400 Mawozo has typically demanded ransoms of around $20,000, it said.

Gang activity in Haiti is so entrenched that even Prime Minister Ariel Henry was forced to backtrack on plans to lay a wreath for the Haitian Revolution leader Jean-Jacques Dessalines on Sunday – a national holiday commemorating his death – during a memorial in Pont Rouge, an area controlled b