The clergy members were kidnapped in the commune of Croix-des-Bouquets, northeast of the capital Port-au-Prince, said Father Gilbert Peltrop, secretary general of the Haitian Conference of the Religious (CHR) association.

"The nation must stand up to fight these thugs," Peltrop told Reuters.

The French citizens included one priest and a nun, he added.

France's Foreign Ministry confirmed in a statement two French citizens had been kidnapped in Haiti but did not provide further details, citing security reasons.

"The crisis and support centre of the ministry of Europe and foreign affairs is fully mobilised as well as our embassy in Haiti, in close contact with local authorities," the statement said .

The kidnappings come less than two weeks after gunmen kidnapped a Haitian pastor and three others during a ceremony that was streamed live on Facebook.

The kidnapping of the seven clergy was carried out by the notorious '400 Mawozo' gang, Haitian news agency Juno7 said.

"The kidnappers demanded a ransom of $US1 million ($A1.3 million)," Juno7 said.

Haiti has been rocked by rising violence in recent years, including a spate of kidnappings for ransoms which have paralysed the economy and Haitian society.

Australian Associated Press