Complex sentence: Some mines, such as the Italian MAT/6 mine are designed to be flail resistant; mines that have been buried for many years may fail to detonate when struck but may still be hazardous.
Split into simpler sentences: Some mines, such as the Italian MAT/6 mine are designed to be flail resistant. Mines that have been buried for many years may become unreliable and fail to detonate when struck, yet they may still be hazardous.