dawn on 6 April, the German armies invaded Greece, while the Luftwaffe began an intensive bombardment of Belgrade. The XL Panzer Corps began their assault at 05:30. They pushed across the Bulgarian frontier into Yugoslavia at two separate points. By the evening of 8 April, the 73rd Infantry Division captured Prilep, severing an important rail line between Belgrade and Thessaloniki and isolating Yugoslavia from its allies. On the evening of 9 April, Stumme deployed his forces north of Monastir, in preparation for attack toward Florina. This position threatened to encircle the Greeks in Albania and W Force in the area of Florina, Edessa and Katerini. While weak security detachments covered his rear against a surprise attack from central Yugoslavia, elements of the 9th Panzer Division drove westward to link up with the Italians at the Albanian border. The 2nd Panzer Division (XVIII Mountain Corps) entered Yugoslavia from the east on the morning of 6 April and advanced westward through the Strumica Valley. It encountered little resistance, but was delayed by road clearance demolitions, mines and mud. Nevertheless, the division was able to reach the day's objective, the town of Strumica. On 7 April, a Yugoslav counter-attack against the division's northern flank was repelled, and the following day, the division forced its way across the mountains and overran the thinly manned defensive line of the Greek 19th Mechanised Division south of Doiran Lake. Despite many delays along the mountain roads, an armoured advance guard dispatched toward Thessaloniki succeeded in entering the city by the morning of 9 April. Thessaloniki was taken after a long battle with three Greek divisions under the command of General Bakopoulos, and was followed by the surrender of the Greek Eastern Macedonia Army Section, taking effect at 13:00 on 10 April. In the three days it took the Germans to reach Thessaloniki and breach the Metaxas Line, some 60,000 Greek soldiers were taken prisoner. Greek-Yugoslav counteroffensive In early April 1941, Greek, Yugoslav and British commanders met to set in motion a counteroffensive, that planned to completely destroy the Italian army in Albania in time to counter the German invasion and allow the bulk of the Greek army to take up new positions and protect the border with Yugoslavia and Bulgaria. On 7 April, the Yugoslav 3rd Army in the form of five infantry divisions (13th "Hercegovacka", 15th "Zetska", 25th "Vardarska", 31st "Kosovska" and 12th "Jadranska" Divisions, with