Violent protests sparked by the death in police custody of African-American George Floyd continued to sweep across the United States on Sunday. Mayors and governors of violent-hit cities and states have been calling for calm after curfews failed to deter the protesters. Almost 62,000 National Guard — the US reserve military force for domestic emergencies — soldiers have now been deployed across 24 states, to help authorities control civil unrest as well as deal with the ongoing coronavirus crisis and bushfires. There have been strict curfews imposed in 40 cities and public transport systems have been shut down, but the restrictions have been largely ignored and many places have again erupted into unrest. Meanwhile on Sunday night, riot police clashed with protesters in New York, Chicago, Philadelphia and Los Angeles, firing tear gas and pepper bullets to try to disperse the crowds. Police vehicles were set on fire and shops were looted in several cities. Police in Washington D.C. have fired tear gas at demonstrators who set fire to properties near the White House. They include a historic church, St. John's Episcopal Church, known as the church of the presidents, near the White House. At least 4,400 people have been arrested over several days of protests, according to a tally compiled by the Associated Press news agency. Arrests have been made over a range of offenses, from looting and blocking motorways to breaking curfew. In Minneapolis, a lorry driver was arrested after reportedly breaching a road barrier before speeding towards a crowd of protesters marching along a major motorway. With looting and riots dominating much of the coverage, there have also been incidents of police departments joining protesters in a sign of solidarity. The Floyd case has reignited anger over police killings of black Americans. — Agencies