 German General Friedrich Freiherr Kress von Kressenstein 's raiding force retaliated to this growing British presence , by attacking the widely dispersed 5th Mounted Brigade on 23 April , Easter Sunday and also St George 's Day , when Yeomanry were surprised and overwhelmed at Katia and Oghratina east of Romani . The mounted Yeomanry brigade had been sent to guard the water pipeline and railway as they were being extended beyond the protection of the Suez Canal defences into the desert towards Romani . 
