Haiti's President Jovenal Moise vowed Monday to do more to combat the country's "scourge" of kidnappings after 10 people, including clergy members and French nationals, were abducted over the weekend.

Kidnappings for ransom have surged in recent months in the capital Port-au-Prince and other provinces, reflecting the growing influence of armed gangs in the Caribbean nation, and the latest abductions on Sunday prompted accusations of government inaction.

Among the 10 kidnapped in Croix-des-Bouquets, a town northeast of Port-au-Prince, were seven Catholic clergies including two French citizens, and a priest and a nun.

A spokesman of Haiti's Bishop's Conference told AFP news agency the kidnappers have demanded a $1 million ransom for the hostages.

Reacting on Monday, Moise vowed he would "not give up" and "do everything the law allows" to secure the kidnapped people's release, and to tackle Haiti's kidnapping problem more broadly.

"I am aware that the state must make more of an effort in the battle against this disaster that is kidnapping and organized crime in the country," he said.

Earlier the Catholic Church had voiced stinging criticism at the government's inaction and noted that Haiti had for some time been witnessing a "descent into hell." 

"The public authorities who are doing nothing to resolve this crisis are not immune from suspicion," the Archdiocese of Port-au-Prince said in a statement.

France opened an investigation Monday for "kidnapping and sequestration in an organized gang."

"The crisis and support center of the ministry as well as our embassy in Haiti are fully mobilized, in close contact with the local authorities," the French foreign ministry said.

Authorities suspect that an armed gang called "400 Mawozo" – which is active in kidnappings – is behind the abduction, according to a police source.

The head of the French-based Society of Priests of St James, which the five abducted priests belong to, said contact had been made and negotiations were ongoing, without elaborating.

The Haitian Conference of Religious (CHR) also slammed the lack of agency by government authorities in a statement and expressed "anger at the subhuman situation through which we have been wading for more than a decade."

"Not a day goes by without weeping and gnashing of teeth, yet the so-called leaders of this country, while clinging to power, are increasingly powerless."

The Haitian government declared a month-long state of emergency in March to restore state authority in gang-controlled areas.

The rise in gang violence and political instability in the poorest country in the Americas has also drawn protesters onto the streets of Port-au-Prince in recent weeks.

This comes as the government remains mired in a political stand-off, with Moise governing by decree even while opponents say his term in office ended in February.

(With input from AFP)