At least 25 people were injured after an explosion in Manhattan Saturday night, emergency workers confirmed to Fox News.The blast was heard on West 23rd Street between 6th and 7th Avenues in the city’s Chelsea neighborhood. Police counterterrorism officers, a bomb squad and firefighters rushed to the scene.All of the injured were expected to survive, the FDNY added. The blast may have originated in a garbage can which was found mangled, investigators added.A witness described the explosion as ‘very forceful,’ telling Fox News it sent a ‘big cloud of black smoke’ into the air as witnesses ran. Another witness said a fireball shot into the air as a nearby building shook.A National Guard member near the scene told Fox News the explosion was so loud that he put on his uniform and raced to the area.Witnesses say FBI and Homeland Security officials are also at the scene. Investigators did not immediately give details on what may have caused the blast. Earlier Saturday, a planned charity run for Marines and sailors was canceled after a pipe bomb exploded in Seaside Park, New Jersey, a 90-minute drive south of New York City.Police blocked off nearby streets as the investigation continued.