A total of four students have been slashed on Long Island this week, and multiple school districts have stepped up security in response, according to officials.

News 12 Long Island has learned two more students were slashed at Uniondale High School on Monday.

Officials say a student snuck a knife past the metal detectors at the school and used it in a fight.

Police say the girl got into an argument with two other girls, and then pulled out a knife and slashed one of the girls in the hand and the other on the cheek. Both victims were treated at the school.

The school says it is reinforcing their security protocols after security officers and teachers were able to diffuse the slashing.

This afternoon, a protest was held outside the school as a result of the recent violence. 

Meanwhile, another teen was stabbed in the chest on his way home from Riverhead High School.

Police are searching for five boys who they say stabbed the teen while he was walking home.

The incident happened Tuesday at 1:30 p.m. while the 16-year-old was around the block from the school.

Police tell News 12 five boys wearing black masks tried to rob the teen behind the Harbor Freight Tools on Old Country Road. The teen is expected to be OK.

Lastly, extra security will remain in place this morning and backpacks will be searched  following a stabbing at Lindenhurst Middle School.

The 13-year-old victim is expected to be released from the hospital in the next few days.

As News 12 has reported, the 12-year-old suspect was arrested on Monday.

Police say they will continue to patrol inside and outside the school for the remainder of the week.