Pedestrians beware: in Puebla’s historic center, a rash of manhole cover thefts has alarmed neighbors and frustrated authorities.

The covers are stolen for their scrap metal value, leaving holes that present a danger both to pedestrians and vehicles. In some cases, neighbors have taken it upon themselves to mark the holes with caution tape or objects, hoping to prevent accidents.

According to a source close to the state’s Public Security Ministry, the manhole covers are worth less than 1,000 pesos each to thieves. The areas of the city with the most robberies are the México-Puebla highway, Vía Atlixcáyotl and the historic center.

Though the covers can be difficult to replace, municipal police have managed to detain at least one alleged thief. Last Sunday, a man was arrested for making off with a cover after a neighbor witnessed the crime and called police.

Puebla is hardly the only area suffering from manhole cover thefts. The problem has also been reported in San Luis Potosí, Tamaulipas and Guanajuato.

“When the rainy season arrives, the problem is accentuated … [citizens] complain but there isn’t much to be done because the authorities do not have sufficient resources to repair all the damage,” said Rubén Guajardo Barrera, a San Luis Potosí state legislator who called for greater enforcement to prevent and punish the thefts.

In July, Tamaulipas water authorities reported that the stolen drain covers were costing them more than 100,000 pesos a week. And in Salamanca, Guanajuato, authorities have started to replace some of the covers with concrete rather than iron, hoping to reduce thefts.

It is not a new problem. The Mexico City government said in late 2015 it had spent more than 17 million pesos to replace stolen manhole covers and drainage grates.

With reports from Periódico Central and El Universal