Madrid - President Barack Obama called on Sunday for greater tolerance, respect and understanding from police officers toward the people they take an oath to protect as well as from individuals who think the police are too heavy handed and intolerant, particularly toward people of color."I'd like all sides to listen to each other," Obama said as he answered a reporter's question after meeting with Spain's acting prime minister, Mariano Rajoy, during his shortened first visit to Spain as president.It was the fourth straight day that Obama has commented on a series of distressing events back home: the fatal shootings by police of black men in Louisiana and Minnesota, and a sniper attack that killed five police officers and wounded seven in Dallas.He said violence against police by anyone concerned about fairness in the criminal justice system does "a disservice to the cause".He repeated that the vast majority of US police officers are doing a good job, but said rhetoric that fails to recognise that will do little to rally allies to support efforts to change a system that is broadly recognised as being biased against minorities."Maintaining a truthful and serious and respectful tone is going to help mobilise American society to bring about real change," Obama said.The president also called for balance from law enforcement. "I would hope that police organisations are also respectful of the frustrations that people in these communities feel and not just dismiss these protests and these complaints as political correctness," he said."It is in the interest of police officers that their communities trust them," Obama said.