Two senior US Democrats have called for stricter gun control following the elementary school shootings in Newtown, Connecticut.Twenty children and six women died in Friday’s assault on Sandy Hook school by a lone gunman who then turned his weapon on himself.Connecticut Governor Dan Malloy said he wanted stronger national limits.And Senator Dianne Feinstein said she would introduce a bill to ban assault weapons as soon as Congress convened.A nationwide ban on certain semi-automatic rifles in the US expired in 2004.President Barack Obama - who shortly after the school attack urged "meaningful action” against gun crime in the US was due to visit Newtown on Sunday. He was to meet families and emergency service workers, and speak at an interfaith vigil at the town’s high school. Ahead of his visit, a service for the victims at St Rose of Lima Roman Catholic Church was abandoned and the church evacuated because of an unspecified threat.Reports from Newtown now say police have given the all-clear. The gunman behind Friday’s shootings has been named in media reports as Adam Lanza, who is said to have killed his mother before driving to the school, opening fire and then killing himself.The state’s chief medical examiner said the gunman used a semi-automatic rifle as his main weapon, and all the victims appeared to have been shot several times, some of them at close range.Speaking on Sunday, Governor Malloy said Connecticut had an existing ban on assault weapons, but the lack of a similar law at federal level made it difficult to keep them out of the state."These are assault weapons. You don’t hunt deer with these things,” he told CNN."One can only hope that we’ll find a way to limit these weapons that really only have one purpose.” Governor Malloy had to break the news to most of the victim’s families on Friday."You can never be prepared for that to tell 18 to 20 families that their loved one would not be returning to them that day or in the future,” he said.