On 2 June the mine which he had constructed beneath the "Polder" bulwark was sprung. A breach forty feet wide was made and the Spanish launched another assault and leaped into the crater. Emerging from the crater and carrying the Polder at last to their surprise were new defences. The besiegers had worked out where the mine was being dug, withdrew from the "Polder", and built a new set of defences (known as the New Polder) directly behind with flanking batteries for the impending assault. The musketeers and pikemen protected by their new works were ready and after giving heavy fire then counterattacked towards the shocked and confused assailants. After they reeled back from a brief but severe struggle, the Spanish retreated suffering yet more heavy losses. Spinola called off further assaults for two weeks while the work on another mine under the Western bulwark continued but he knew that he had to take Ostend before Maurice could take Sluis. On 7 June, further reinforcements arrived at the stronghold – five companies in all: two English, two Scottish, and one from Friesland, all of them under the command of Charles Fairfax.