On 9 September, Italian aircraft start preparation bombardments for the invasion of Egypt. Four days later, Italian infantry attacked and advanced as far as Sidi Barrani before digging in, west of the main British position at Mersa Matruh. In East Africa, after some initial offensive actions, the Italian conquest of British Somaliland began in August and annexed the colony. After crossing the Albanian border, Italian forces began the Greco-Italian War by invading Greece on 28 October. The Greek army repulsed the Italian attack and commenced a counter-offensive on 14 November, which pushed Italian forces back into Albania.