Police in <a href="https://www.thenationalnews.com/tags/california/" target="_blank">California</a> were on Sunday hunting for suspects in connection with a mass shooting in a busy nightlife district of central Sacramento, in which six people were killed and 12 injured. Police said on Sunday that several shooters were involved. Sacramento Police Chief Kathy Lester told reporters that nobody was in custody over the shooting, which occurred at about 2am near the Golden 1 Centre, a sporting arena and concert venue in the city centre. “We are asking for the public's help in helping us to identify the suspects in this and provide any information they can to help us solve this,” she said. Police were patrolling the area when they heard gunfire. At the scene, they found a large crowd gathered on the street and six people dead. Another 10 were taken or took themselves to hospital. Police said several blocks would be closed while they investigate but released no details about the victims. Videos posted online showed people shouting and running from the sound of gunfire but the footage could not be verified. On Monday, President Joe Biden said America "must do more than mourn; we must act." "Ban <a href="https://www.thenationalnews.com/world/the-americas/biden-to-go-after-merchants-of-death-who-sell-illegal-guns-1.1247716" target="_blank">ghost guns</a>. Require background checks for all gun sales. Ban assault weapons and high-capacity magazines. Repeal gun manufacturers’ immunity from liability," he said in a statement. "These are just a few of the steps Congress urgently needs to take to save lives." Ghost guns are untraceable firearms, often made from various components bought on line and put together at home. US politicians have for years struggled to balance the rights of gun owners and public safety. “The numbers of dead and wounded are difficult to comprehend,” Mayor Darrell Steinberg posted on social media. "Rising gun violence is the scourge of our city, state and nation, and I support all actions to reduce it." The incident came only weeks after a man shot and killed his three children and a fourth person before taking his own life in Sacramento, the state capital and a city of 500,000 people.