The display was a violation of their agreement with the Palestinian Authority president, Mahmoud Abbas, not to carry or fire their weapons in public.
The Palestinian Authority president says there will be no quick decision on whether to continue talks with Israel.
Mahmoud Abbas, the Palestinian Authority president, declared a day of mourning for the children and ordered security forces deployed in Gaza.
She said her father was a close acquaintance of the father of Mahmoud Abbas, the Palestinian Authority president.
A spokesman for the Palestinian Authority president ,Yasser Arafat, denounced the plans and asked the international community to intervene.
The Palestinian Authority president, Mahmoud Abbas, said he was hopeful.
Barghouti was a candidate in the election for Palestinian Authority president, to fill the vacancy created by the death of Yasser Arafat.
The death sentence requires the approval of the Palestinian Authority president, Mahmoud Abbas, who is not expected to approve it.
She described the Palestinian Authority president as a "man who is committed to the agreements that the Palestinians have signed over the last decade or so."
The Palestinian Authority president, Mahmoud Abbas, condemned the bombing, as he has done with past attacks.