At least six people have been killed and 11 others injured in separate shooting incidents across the US State of Chicago during the weekend, officials say.Chicago authorities said on Monday that police were investigating the death of a 42-year-old man who was shot in the head on Sunday. The man, named Charles Jones, was pronounced dead at Northwestern Memorial Hospital at about 3:30 a.m. local time. Another man in his late 20s was also killed on Sunday after being shot in the armpit. He was taken to a suburban hospital but died of gunshot. Two others were killed on Saturday, including Fearro Denard, 18, and a 29-year-old man who received a gunshot near President Barack Obama's South Side home. A 17-year-old and 22-year old were also killed in shooting incidents on Friday. Shooting incidents across the US continue unabated as the nation’s lawmakers have refused to consider legislation to better control guns and enforce stricter background checks for gun buyers following last December’s shooting massacre of 20 children and seven adults at a Connecticut elementary school. Every year, more than 30,000 people are shot and killed in the US.