The US airforce has adopted a new battlefield technology used by Israel to fight ISIS. Known as the 'knock operation' it is used to get women and children out of the threat area when an attack is about to be launched. It is used to minimise civilian casualties as ISIS has come known to use human shields. The method has been used by the US to attack an ISIS financier said to be a major distributor of funds to fighters. It involves deployment of a Hellfire on top of a building using an air burst so as not to destroy the roof to warn women and children about an attack.