The 4 April pause in the 3rd Army advance allowed the other armies under Bradley's command to reach the Leine River, about 50 mi (80 km) east of Paderborn. Thus all three armies of the 12th U.S. Army Group were in a fairly even north-south line, enabling them to advance abreast of each other to the Elbe. By 9 April, both the 9th and 1st Armies had seized bridgeheads over the Leine, prompting Bradley to order an unrestricted eastward advance. On the morning of 10 April, the 12th U.S. Army Group's drive to the Elbe began in earnest.[28] Although the Elbe River was the official eastward objective, many American commanders still had their eyes on Berlin. By the evening of 11 April, elements of the 9th Army's 2nd Armored Division—seemingly intent on demonstrating the ease with which their army could take that coveted prize—had dashed 73 mi (117 km) to reach the Elbe southeast of Magdeburg, just 50 mi (80 km) short of the German capital. On 12 April, additional 9th Army elements attained the Elbe and by the next day were on the opposite bank hopefully awaiting permission to drive on to Berlin. But two days later, on 15 April, these hopes had to be abandoned. Eisenhower sent Bradley his final word on the matter: the 9th Army was to stay put – there would be no effort to take Berlin. Simpson subsequently turned the attention of his troops to mopping up pockets of local resistance.[28] American tanks in Coburg on 25 April In the center of the 12th U.S. Army Group, Hodges? 1st Army faced somewhat stiffer opposition, though it hardly slowed the pace. As its forces approached Leipzig, about 60 mi (97 km) south of Magdeburg and 15 mi (24 km) short of the Mulde River, the 1st Army ran into one of the few remaining centers of organized resistance. Here the Germans turned a thick defense belt of antiaircraft guns against the American ground troops with devastating effects. Through a combination of flanking movements and night attacks, First Army troops were able to destroy or bypass the guns, moving finally into Leipzig, which formally surrendered on the morning of 20 April. By the end of the day, the units that had taken Leipzig joined the rest of the 1st Army on the Mulde, where it had been ordered to halt.[29] Meanwhile, on the 12th U.S. Army Group's southern flank, the 3rd Army had advanced apace, moving 30 mi (48 km) eastward to take Erfurt and Weimar, and then, by 12 April, another 30 mi (48 km) through the old 1806 Jena Napoleonic battlefield area. On that day, Eisenhower instructed Patton to halt the 3rd Army at the Mulde River, about 10 mi (16 km) short of its original objective, Chemnitz. The change resulted from an agreement between the American and Soviet military leadership based on the need to establish a readily identifiable geographical line to avoid accidental clashes between the converging Allied forces. However, as the 3rd Army began pulling up to the Mulde on 13 April, the XII Corps—Patton's southernmost force—continued moving southeast alongside the 6th U.S. Army Group to clear southern Germany and move into Austria. After taking Coburg, about 50 mi (80 km) south of Erfurt, on 11 April, XII Corps troops captured Bayreuth, 35 mi (56 km) farther southeast, on 14 April.[30] As was the case throughout the campaign, the German ability to fight was sporadic and unpredictable during the drive to the Elbe-Mulde line. Some areas were stoutly defended while in others the enemy surrendered after little more than token resistance. By sending armored spearheads around hotly contested areas, isolating them for reduction by subsequent waves of infantry, Eisenhower's forces maintained their eastward momentum. A German holdout force of 70,000 in the Harz Mountains—40 mi (64 km) north of Erfurt—was neutralized in this way, as were the towns of Erfurt, Jena, and Leipzig.