NEW : The President 's office says a working group will meet with the opposition . Comment: Interior Ministry says some protesters tried to march on government buildings . The new law was passed by lawmakers loyal to Ukraine 's president in a show of hands .
NEW : The President 's office says a working group will meet with the opposition . 30 police officers were injured in clashes , the Interior Ministry says . Interior Ministry says some protesters tried to march on government buildings . The new law was passed by lawmakers loyal to Ukraine 's president in a show of hands .