An estimated 3,000 East German youths, gathering near the Berlin Wall in an attempt to hear a West Berlin concert by Eurythmics, tangled with baton-wielding police Sunday night after they began chanting anti-government political slogans. About 1,000 of the youths, who shouted "The Wall must go!" and "Down with the pigs (police)" as they marched, were moving toward the Soviet Embassy on East Berlin's Unter den Linden when police sealed off the street and began arresting the youths. About 20 remained in custody overnight, police officials said Monday. Another West Berlin concert--this one, on Saturday, given by David Bowie--brought hundreds of youths onto East Berlin streets, but that crowd dispersed without incident.