Twelve people have been killed and several more have been wounded after shots were fired at one of the biggest naval command buildings in the US.Authorities said at least 12 people were killed in shootings at the Washington Navy Yard on Monday morning. Shots were fired at around 8:20 a.m. ET at the Naval Sea Systems Command Headquarters building where nearly 3,000 people work. D.C. Metropolitan Police Chief Cathy Lanier has said one of the suspected shooters have been killed while authorities are searching for two other possible shooters involved in the incident at the Navy Yard. Officials say the suspected shooters are wearing military style clothing. The sea systems command is the biggest of the US Navy’s five system commands and is responsible for building, buying, and maintaining ships and submarines. Police officers closed streets near the Navy Yard and a “shelter in place” order was issued for the personnel. Moreover, US Capitol Police, responsible for protecting US Congress, confirmed enhanced security at Capitol Hill. Meanwhile, an elementary school near the installation in Southeast Washington was on lockdown. An unnamed White House official has told The Washington Post that President Barack Obama has been briefed on the situation. “The President directed his team to stay in touch with our federal partners, including the Navy and FBI, as well as the local officials. We urge citizens to listen to the authorities and follow directions from the first responders on site,” said the administration official.