They once numbered as many as 1.5 million, living underneath tattered tents and in squalid camps dotted across Haiti’s congested capital and nearby cities.

But four years after the country’s devastating earthquake, the number of Haitians displaced by the Jan. 12, 2010, disaster and still living in camps has dropped to 137,553 in 243 camp sites, the International Organization for Migration said Monday.

Still, there are some worrying trends despite the 91 percent drop: families unable to pay rent are returning to the camps, while other camps are showing little to no prospect of ever being emptied, the Geneva-based humanitarian group said in its latest report.

“The phenomenon of new families moving into camps and families splitting and occupying more tents constitutes a worrying trend observed in 68 [camp] sites,” the report said.

Reversing the trend and emptying out the remaining camps require a strong commitment from the Haitian government to come up with solutions, the report said.

Among the report’s other highlights: None of the 30 camps that closed between January and March did so because of forced evictions, an ongoing concern for international human rights and humanitarian groups.

Most of the closures were the result of a government-led effort to relocate people from squalid camps into permanent housing with the help of rental subsidies. The initiative is financed by the international community.

Clément Bélizaire, director of the government’s camp relocation and rehabilitation program, said despite the challenges the progress shows the government remains committed to making tent cities a thing of the past. Since June 2011, 339 have closed.

“Since 1986, this the first time I’ve seen so many projects being implemented, and in many ways, a lot of neighborhoods today are in much better shape than before the quake due to significant investments made in infrastructures,” he said.