UPDATE 1-German states send more police to Hamburg as G20 violence escalates

HAMBURG, July 7 (Reuters) - Protesters injured 160 police officers in clashes and torched cars, barricades and rubbish bins on Friday as leaders from the world's top economies gathered for a summit in Hamburg.
Police forces around Germany dispatched reinforcements to help 15,000 police already deployed to the northern port city for the G20 summit as the violence escalated. At least 15 people were arrested and dozens more held for questioning.
German Finance Minister Wolfgang Schaeuble cancelled an appearance in downtown Hamburg on Friday morning due to security concerns, and police declined to clear U.S. First Lady Melania Trump's motorcade
to leave her hotel to join in a tour of the city's historic harbour, her spokeswoman said.
"She has already missed a good portion of it. It's too bad, she was really looking forward to it," Stephanie Grisham said.
Andy Grote, Hamburg's interior minister, said 160 police officers had been injured in what he called "frightening" violence. Three officers required treatment in hospital, police said, noting that protesters had also used slingshots as well as thrown bottles and stones.
City police chief Ralf Martin Meyer told reporters that tight security around the conference area had caused protesters to fan out around Hamburg, forcing police to request 900-1,000 further officers as reinforcements from throughout Germany.
"We are focusing on securing corridors to make sure that the path for (leaders') convoys is clear," said Meyer.
"We have to expect everything, and we are expecting everything," Grote said.Police said violence that erupted during marches on Thursday continued into Friday, with far left protesters slashing the tires of a car belonging to Canada's G20 delegation and smashing windows of the consulate of Mongolia.
A police spokesman said only small numbers of far left or anarchist protesters were involved in disturbances, with the majority of an estimated 100,000 demonstrators in the city remaining peaceful. Some 12,000 took part in the main march.
On Friday, smaller groups of protesters attacked both manned and empty police cars, one of which was hit by a petrol bomb, police said.
One of the many police helicopters patrolling the skies was nearly struck by a rocket flare, police said in a statement. On Thursday the pilots of another helicopter sustained eye injuries after a laser was directed against them.
Police said they continued to dispel street blockades throughout Hamburg.