New Haven school officials said two students brought knives with them to class Tuesday.
A student riding the bus to Lincoln-Bassett School was found to be in possession of a concealed knife.
Another student on the bus was found in possession of a lighter, which other students thought was knife, according to school officials.
The school district said in a separate incident at Clinton Avenue School, a knife fell out of a student's pocket.
"It is a serious offense to carry a weapon or to threaten the safety of our students. The schools are carrying out appropriate sanctions," a spokesperson for the school district said in a statement.
Both schools are for children in grades K-8. It is unknown how old the students who brought the knives are.