Kidnappers have freed two Swiss women snatched off the streets of Haiti's capital and held for five days, officials said Thursday.

It is the first reported kidnapping since Haiti suffered a magnitude-7 earthquake with catastrophic damage on Jan. 12. More than 5,000 prisoners fled jails that collapsed or were damaged in the temblor. Only about 200 have been captured.

Doctors Without Borders, among hundreds of international aid agencies that have flooded into Haiti to help, refused to identify the victims of Friday's kidnapping.

But a security alert sent to nongovernmental agencies, obtained by The Associated Press, said the two were Swiss women working for the agency. The alert said that they were kidnapped at night near the posh Plantation restaurant in a Petionville suburb.

Doctors Without Borders spokesman Michel Peremans said the victims were released Wednesday night. He would not say if a ransom was paid.

Aid groups told the AP that they have imposed dusk-to-dawn curfews following the kidnapping and amid increasing signs of insecurity in the capital, Port-au-Prince. Doctors still treating earthquake victims report that they are seeing many gunshot wounds, and it is common to hear cracks of gunfire at night.

Many women have reported being raped in some of the hundreds of makeshift tent camps set up by people whose homes collapsed or were damaged by the quake.

The Swiss aid workers were held during a weekend in which most of the thousands of U.S. troops that had helped distribute aid and provide security following the quake were leaving the country.

A small number of troops — the U.S. military has not said how many — have remained to help 10,000 Haitian police officers and 10,000 U.N. peacekeepers reassert control.

Kidnappings were rare in Haiti until 2004, when abductions took place during the bloody chaos that followed the ouster of President Jean-Bertrand Aristide. Foreigners were often targeted, but Haitians were taken in much larger numbers.

Political officials, foreign aid workers and deeply impoverished Haitian children were all targeted in the kidnappings, which typically spiked before Christmas as bandits sought money to buy presents.

Crackdowns by U.N. police and a strengthened — and increasingly less corrupt — Haitian police force helped curb the crime in the 18 months leading up to the earthquake, but some of those suspected of heading kidnapping rings escaped from the national penitentiary during the disaster.