Sales of bulletproof backpacks for children and other products like armored pants have shot up in the United States over the past few days following the massacre at the elementary school in Newtown, Connecticut, where Adam Lanza gunned down 20 youngsters and six adults.

Rich Brand, operations director at the 2nd Amendment store, which specializes in military and security products, said Thursday on the CNN network that sales are up "by some 500 percent" and that many customers are "desperate" parents looking for ways to protect their kids in "extreme" situations.

One of the products most in demand are children's armored backpacks, which can cost as much as $400.

These backpacks are designed with a material able to stop handgun bullets but not those from a rifle like the one used by Lanza in the shooting at Sandy Hook Elementary School in Newtown.

In Austin, Texas, the online store that specializes in bulletproof products said its sales have increased by 50 percent and that its newest customers are, above all, schools and day care centers.

Lawmakers in several U.S. states are proposing bills that would allow teachers and other school employees to bear arms to protect students.

United States President Barack Obama promised Wednesday to present "specific" proposals in January for greater gun control, describing the violence caused by firearms as an "epidemic" that daily strikes a country still shaken by the Newtown tragedy. EFE