Meanwhile Ahmed Fedil was working his way slowly southward along a deep khor which runs almost parallel to the Blue Nile and is perhaps twenty miles from it. As soon as the position of the Dervish Emir was definitely known, Colonel Lewis moved his force, which had been strengthened by detachments of the Xth Soudanese, from Karkoj to Rosaires. Here he remained for several days, with but little hope of obstructing the enemy's passage of the river. On the 20th of December, however, full--though, as was afterwards found, not very accurate--information was received. It was reported that on the 18th Ahmed Fedil had reached the village of Dakhila, about twenty miles south of the Rosaires post; that he himself had immediately crossed with his advanced guard, and was busily passing the women and children across the river on rafts. On the 22nd, therefore, Colonel Lewis hurried the Sheikh Bakr up the west bank to cut off their flocks and harass the Dervishes who had already crossed the river. The irregulars accordingly departed; and the next day news was brought that the Dervish force was almost equally divided by the Blue Nile, half being on one bank and half on the other. At midday on the 24th the gunboats Melik and Dal arrived from Omdurman with a detachment of 200 more men of the Xth Soudanese under Major Fergusson, and thirty men of the IXth Soudanese under Captain Sir Henry Hill. With this addition the force at Colonel Lewis's disposal consisted of half the Xth Soudanese, a small detachment of the IXth Soudanese, two Maxim guns, and a doctor. Besides the regular troops, there were also the band of irregulars under the Sheikh Bakr, numbering 380 men, 100 men under the Sheikh of Rosaires, and a few other unclassified scallywags. Colonel Lewis determined to attack what part of Ahmed Fedil's force still remained on the east bank of the river, and on Christmas Day, at five o'clock in the afternoon, he marched with every man he could muster in the direction of Dakhila.