"They must've thought I was hungry", says PM Julia Gillard, brushing off another a sandwich thrown at her during a school visit.

A BOY in a blue hoodie has been identified as the alleged chief suspect for today's sandwich throwing incident.

A white-bread missile was thrown at Prime Minister Julia Gillard during a visit to Lyneham High School in Canberra this morning.

Ms Gillard was walking in a crowded foyer at Lyneham High School - where she was announcing the ACT had signed up to her Gonski reforms - when the salami sandwich was thrown.

It was lobbed from behind, over the top of her head, and landed at her feet at 11.46am.

The sandwich was not toasted and it also had not been sliced.

Earlier this month Queensland teen Kyle Thomson was suspended from Marsden State High School after a similar incident during a visit by the Prime Minister.

The 16-year-old later professed his innocence.

He said he had tried to knock the sandwich out of another student's hand.

OPINION: "She is the Prime Minister of our country, and that office alone should be enough to keep her safe from flying school lunches"

Asked if she was disappointed to about today's sandwich incident, Ms Gillard joked the thrower "must have thought I was hungry".

Dozens of excited school kids, one sandwich & an agreement that will get the children of the ACT a world class education for generations.JG — Julia Gillard (@JuliaGillard) May 30, 2013

It is unclear what steps are being taken to discipline the culprit, with principal Colleen Matheson declining to comment. Support staff and teachers at the school were disappointed and on edge.

One student was on the receiving end of a severe dressing down, apparently unrelated to the little lunch attack.

"I've already been humiliated by one child today, don't let it happen with another," a teacher told him in front of the media.

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