A pre-dawn fire has swept through a drug rehabilitation centre in a town on Lima's outskirts, killing 14 people in the second blaze in Peru this year to kill addicts locked up in a private treatment residence.

The only known survivor of the blaze at the Sacred Heart of Jesus clinic escaped by jumping from the building's second floor after the blaze broke out about 4am on Saturday, his brother said.

Local health director Pablo Cespedes said officials did not yet know what caused the blaze. There were media reports a patient may have set his mattress alight. Thirteen bodies were found in bedrooms on the second floor and one on the first floor of the two-storey home in Chosica, about 19 miles (32km) east of Lima, the coastal capital, Cespedes said.

Rescue efforts were complicated by locked doors and barred windows, said fire chief Fernando Campos. "The doors were padlocked shut. We had to use tools to get in the front door. On the second floor the windows have bars," he told reporters at the scene.

The apparent lone survivor, 39-year-old Luis Zevallos, jumped out of the building from a section of the second floor that lacked bars, said his brother, Jose Zevallos. "His friends were afraid and didn't [jump]. He's got burns on his face but it's not too serious. It's a miracle he's alive."

The aunt of an 18-year-old who died in the fire, Jennifer Rugel, said drug rehabilitation centres in Peru, as a rule, "seal their doors with locks because those interned want to escape and are there against their will".

She said by phone from the morgue where police took the 14 bodies that her nephew, Marco Cespedes, had to be interned because he was selling objects from his home to buy drugs.

The local health director, Cespedes, said the Sacred Heart clinic was licensed but that a 2011 inspection recommended physical improvements to prevent overcrowding and said it needed professional health care workers.

The owners of the clinic could not immediately be located for comment.

After a 28 January fire at a Lima rehab residence for addicts claimed 29 lives, government officials acknowledged that the state has limited capacity for treating drug addicts.

"The state has 700 beds for 100,000 drug-dependent people. That's the root of the problem," the country's drug czar, Carmen Masias, said in radio interview the following day.

A 2010 study by the agency she runs, Devida, counted 222 private rehabilitation centres in Peru, 80% of them unlicensed and many lacking doctors and psychologists.