At least six people were killed in bomb attacks in Iraq on Tuesday, including a device which blew up in a mock coffin during a demonstration, security sources said. Dozens of people took part in the protest in Khales, 65 kilometres (40 miles) north of Baghdad, to demand stiff penalties for the perpetrators of anti-Shiite attacks in the city, the local security operations command said. The demonstrators were carrying a mock coffin when a booby-trapped device exploded inside the box, killing three people and wounding seven, an official at the centre told a foreign news agency. Sectarian tensions remain high in Khales, a city which in 2006-2007 was a battleground between Sunni insurgents of Al-Qaeda and Shiite militias. At the end of May, a car bombing in a Khales marketplace killed 30 people, two months after another 42 people perished in a double bomb attack near a coffeeshop and a restaurant.