Students returned to school Tuesday in Newtown, Connecticut, as the small northeastern town reels from one of the worst school shootings in U.S. history.

Schools opened two hours late as parents, educators and police hoped to resume some normalcy, four days after a gunman opened fire at an elementary school, killing 20 children and six adults.

Classes were resuming at all the town's schools except Sandy Hook Elementary School, where the attack occurred. Town officials say plans are under way to relocate students who attended Sandy Hook to a nearby town.

The horrific shootings have sparked another debate on gun control in the United States. Several Democratic Party lawmakers have called for a new push to restrict sales of guns and ban military-style assault weapons.

California Senator Dianne Feinstein, the author of an assault weapons ban that lapsed in 2004, said she will introduce new legislation this week. The White House says President Barack Obama would support reinstating the ban and legislation that closes the gun show loophole, which allows people to purchase guns from private dealers without undergoing background checks.

Authorities believe the shooter, 20-year-old Adam Lanza, killed his mother at home and then took her guns, including a military-style rifle, with him to the school. Lanza shot himself as police approached. Investigators say the motive remains unclear.

Funerals were held Tuesday for two six-year-old victims. The first two young victims, six-year-old boys, were laid to rest on Monday. More services are planned this week.

Mourners have placed stuffed animals, flowers, notes and paper angels outside the funeral homes and other locations in the town in tribute to the children, who were six and seven years old, and the adult victims.

All the adults killed were women and included the school's principal, who is reported to have tried to stop the shooter and a teacher who is credited with saving lives by putting herself between students and the attacker.

Friday's attack was the second-worst school shooting in U.S. history. The worst occurred in 2007, when a gunman killed 32 people at Virginia Polytechnic Institute and State University in Blacksburg, Virginia. Before that, the deadliest U.S. school shooting was the 1999 rampage at Columbine High School in Littleton, Colorado, where two teenagers killed 13 students and staff before killing themselves.