Heart-rending funerals were held Monday for two six-year-old boys, as America began to say farewell to the 20 children slain in a school shooting that has sparked calls for new gun laws.

The first burials, held under raw, wet skies, were of a pair of boys who were among those shot in Sandy Hook Elementary School, in Newtown, Connecticut. On Tuesday, the first of the girls, also aged six, was to be laid to rest.In all, on Friday, the gunman slaughtered 20 children aged between six and seven, six adults working at the school and his own mother, before turning one of his arsenal of high-powered firearms on himself.

"You see little coffins and your heart has to ache," said state governor Dannel Malloy.The family of six-year-old Jack Pinto gathered at a funeral home in a century-old building in the center of the Connecticut town. Some 20 children of different ages came to bid him farewell.Jack Wellman, an eighth-grader who helped coach Jack in wrestling, said teammates placed their sports medals in his coffin.

"He was an excellent kid," Wellman said afterwards.Another well-wisher was overwhelmed. "I just cannot describe it, it was sad," she said. "Our hearts are heavy."All schools in this prosperous and picturesque town northeast of New York City were shut until at least Tuesday and the blood-spattered elementary school itself was to remain a closed crime scene indefinitely, authorities said.

"Healing is still going on," Newtown police Lieutenant George Sinko said.In the nearby town of Ridgefield, reports of a suspicious person prompted the brief lockdown and deployment of police Monday at schools, in a sign of the jitters in the United States in the wake of the killings.For Newtown, a quiet suburban community where the 20-year-old killer lived with his well-off mother, the start of funerals did nothing to heal wounds.

But the crime, in which the shooter carried a high-powered, military style rifle and two handguns, may have spurred change in the political landscape regarding rules on weapons ownership.The Senate held a moment's silence in Washington, as several Democratic lawmakers who had previously opposed gun control changed their stance.

Late Sunday, President Barack Obama joined a vigil in Newtown and pledged to work for an end to mass shootings, which have now become a regular event in the United States -- with half-a-dozen massacres since Obama took office.