PHNOM PENH (Reuters) - Cambodia launched a crackdown on bogus orphanages on Thursday, many of which are set up to attract donations from tourists, with the aim of returning about 3,500 children who were not orphans to their families, a government minister said.

About 17 percent of Cambodians live below a national poverty line and some families who are too poor to look after their children send them to orphanages in the hope they will be taken care of and given an education.

Many orphanages have opened over recent years, some unlicensed, unsafe and with few real orphans, raising concerns about neglect and abuse.

The boom has matched a surge in foreign tourists to the Southeast Asian country, one of the world’s poorest.

Some social workers have appealed to tourists to stay away from orphanages saying that so-called orphanage tourism enables child exploitation.

“There are many abuses inside orphanages,” Minister of Social Affairs, Veterans and Youth Rehabilitation Vong Sauth said in a speech at the launch of the plan.

A recent government survey found 16,579 orphans living in 406 orphanages across Cambodia, far more than expected, officials said, adding that 38 percent of the orphanages had never been inspected.

Vong Sauth said 80 percent of the 16,579 children in orphanages were not actual orphans and under the government plan, 3,500 of them would be returned to their families by next year.

Sar Bunthoeun, director of Cambodian Children’s House of Peace, an orphanage in Siem Reap in northwest Cambodia, said he supported the government plan, adding that problems were common in orphanages, but he denied any abuses at his.

The U.N. children’s agency UNICEF, which is working with the government to reunite children with their families, said poverty should not be a justification for the removal of a child from parental care.

“Children living in un-regulated and uninspected institutions are more at risk of neglect, as well as physical and sexual abuse and trafficking,” said Debora Comini, UNICEF representative to Cambodia.

She urged tourists to be wary of appeals for donations from orphanages.