Officials at Berlin's Holocaust memorial say repair work is underway on hundreds of the concrete blocks that make up the 7-year-old monument, which have developed potentially dangerous cracks.

Memorial foundation spokesman Uwe Neumaerker said Friday experts say the damage to 380 of the 2,711 blocks is so bad that pieces of concrete could fall off and hit visitors wandering through the undulating field of slabs.

Each affected block will be shored up with one or two steel bands.

The damage, blamed on the weather, has been a problem for several years. The foundation unsuccessfully tried to fix the blocks with resin in 2008.

The monument to the 6 million Jews killed by the Nazis was opened in 2005 and is one of Berlin's top tourist attractions.