Angela Merkel leads ceremonies to mark 20 years since collapse of Berlin Wall . The ceremony was attended by German President Joachim Gauck, who said the wall had been a symbol for freedom and democracy in Europe. We can not allow oppression , defined and justified by religion or tribe to replace that of ideology . Merkel says Germany still has far to go in its unification process .
Angela Merkel leads ceremonies to mark 20 years since collapse of Berlin Wall . The ceremony was attended by German President Joachim Gauck, who said the wall had been a symbol for freedom and democracy in Europe. Merkel says Germany still has far to go in its unification process .