These bombs are particularly dangerous to civilians because they release a number of smaller submunitions over a wide area and consistently leave behind unexploded bomblets that remain dangerous decades after the military conflict has ended. On Friday, more than 100 nations formally agreed to ban the use of cluster bombs and destroy their stockpiles(備蓄)of the weapon. However, the biggest makers and users of the devices, the US, Russia, China, Israel, India and Pakistan, were noticeably absent from the talks.