WATERTOWN, Mass. (WKTV/AP) - Chaos has erupted in a neighborhood outside Boston, where there reports of explosions and shootings. It is not clear if some of the events are connected, and it is not known if any of these events are connected to the Boston Marathon Bombings on Monday, outside of a nervous and alert community. Dozens of officers and National Guard members are in Watertown, where television outlets report that gunfire and explosions have been heard. Authorities early Friday were calling for somebody to get on the ground and put their hands up and a loud thud was heard after someone shouted "fire in the hole." Reporters are being told to move away from the scene. A police officer told a reporter: "If you want to live, turn off your cell phone." The tense situation followed an hours-long lockdown at the Massachusetts Institute of Technology, where a campus police officer was shot and killed while investigating a disturbance on the Cambridge campus. Multiple news agencies reported that some man was in custody, but is not clear whom or for what incident. The FBI released photos Thursday evening of two men they say are suspects in the bombings at the Boston Marathon.