RIO-DE-JANEIRO, October 21 (RIA Novosti) - Sixteen inmates of a small prison in the southern Brazilian state of Parana have escaped by digging a 4-meter (13-foot) tunnel into a neighboring kindergarten, local media reported Tuesday.

The Astorga prison, which can house 66 prisoners, is guarded by only one prison guard on weekends. Local police said the 16 escapees managed to saw through the bars of their cells and dig the 4-meter tunnel over the weekend, as the only guard on duty failed to watch over the inmates.

The breakout was committed early on Monday morning, when the kindergarten was empty.

It was the second such escape in the past six months. In May, another group of inmates also dug a tunnel into the kindergarten.