Pupils cowered in fear and pleaded for their lives as a 12-year-old boy went on a rampage with a handgun in the US, waving the weapon at classmates and shooting dead a maths teacher.

A boy opened fire with a semi-automatic handgun at his Nevada school yesterday, killing a maths teacher who was trying to protect pupils and wounding two 12-year-old classmates, before turning the weapon on himself.

Two people killed in a US school shooting were a staff member and a student who was probably the attacker, police said.