The Boer commander, Commandant Cornelius Wessels, presented Kekewich with an ultimatum on 4 November, demanding the town's surrender. Kekewich replied the same day, stating: “...you are hereby invited to effect the occupation of this town as an operation of war by the employment of the military forces under your command”. When the siege of Kimberley itself began in earnest on 6 November, the situation favoured an attack. The Boers were in control of the railway from the Orange River to Mafeking, while arms and ammunition were in short supply in Kimberley. On 7 November, the Boers started shelling the town. Communication with the outside world was not seriously impeded however. The Boer strategy was not to attack the town in a full battle, but rather to wait for the defenders to capitulate, all the time wearing them down with shelling. The defenders tried to send the large contingent of migrant native labourers that was working in the mines home, but twice the Boers drove them back into the town in an apparent attempt to put pressure on the limited food and water supply.