SAO PAULO — Prison guards foiled a new attempt to smuggle a cell phone into a Brazilian prison by carrier pigeon — this one wearing a tiny backpack — and said Friday that the practice is becoming almost commonplace.

An exhausted pigeon wearing a small makeshift backpack was intercepted just outside walls at the Danilo Pinheiro prison near the city of Sorocaba, said a spokesman for the Sao Paulo State Prison Affairs department. The representative spoke on condition of anonymity because he was not authorized to comment on the matter with the press.

Inside the cloth sack was a cell phone and a piece of paper with the name of the inmate who was waiting for the phone, the spokesman said. He declined to reveal the name of the inmate.

"The use of carrier pigeons to smuggle cell phones into prisons is becoming almost commonplace," he said. "Guards now keep a sharp eye on pigeons as well as on inmates."

In March, guards at the same prison spotted a pigeon resting on a wire with a small cloth bag tied to one leg. They lured the bird down with food and discovered components of a small cell phone in the bag.

In May, police foiled a plot to smuggle cell phones into a maximum-security lockup using a remote-control model helicopter at another Brazilian prison.

Imprisoned Brazilian gangsters use cell phones to coordinate criminal activity outside and inside an overcrowded prison system where torture, killings and gang violence are routine.

In 2006, Sao Paulo's notorious First Capital Command gang — whose leaders are based in prison — used cell phones to launch a wave of assaults on police, banks and buses that left more than 200 people dead.