By Huseyin Hayatsever and Daren Butler ANKARA (Reuters) -Turkey will attack militants with tanks and soldiers soon, President Tayyip Erdogan said on Tuesday, signalling a possible ground offensive against a Kurdish militia in Syria after retaliatory strikes escalated along the Syrian border. His comments came as Turkish artillery kept up bombardment of Kurdish bases and other targets near the Syrian towns of Tal Rifaat and Kobani, two Syrian military sources told Reuters. “We have been bearing down on terrorists for a few days with our planes, cannons and guns,” Erdogan said in a speech in nor…