Tens of thousands of Palestinians rushed into Gaza streets to mourn Yasser Arafat (search) Thursday as others in the West Bank reacted with tears and tributes. Israel responded by sealing the borders of Palestinian territories.

The Palestinians in Gaza clutched flags and his photograph and waved the trademark headscarf of the leader considered the national patriarch.

Black smoke from burning tires rose across the Gaza Strip. Dozens of children ran through the streets, many promising to carry out his legacy.

In the West Bank city of Ramallah (search), Palestinian flags at Arafat's battered compound were lowered to half staff. Television broadcast excerpts from the Quran (search) with a picture of Arafat in the background.

Israel closed the West Bank and Gaza Strip borders and sent troop reinforcements to the areas, while beefing up security at Jewish settlements amid concern over possible Palestinian rioting in the coming days.

"The Israeli Defense Forces are deploying to allow a dignified funeral ceremony for chairman Arafat," an army statement said.

Palestinian Cabinet minister Saeb Erekat told The Associated Press that the parliament speaker, Rauhi Fattouh, will be sworn in as Palestinian Authority president in place of Arafat in the coming hours.

Yasser Abed Rabbo, a top Arafat aide, said Arafat would be buried on Saturday in Ramallah in what he called a "national day of farewell."

A memorial service was to be held in Cairo, Egypt, on Friday.

Palestinian militant groups Hamas (search) and Islamic jihad, Arafat's main political rivals, expressed sorrow and paid tribute.

Sami Abu Zuhri, Hamas' spokesman in Gaza, called on the group's supporters to honor Arafat and work toward national unity.

"We lost by his death one of our great symbols and one of the main focuses of our national struggle and identity," Abu Zuhri told The Associated Press.

Islamic Jihad spokesman in Gaza Nafez Azzam said "with hearts full of belief in God's will we mourn President Yasser Arafat who was a great leader for the Palestinian people."

In the Jebaliya refugee camp, Gaza's largest, university students and supporters of Arafat's Fatah movement gathered in shock and sadness after learning of his death in a Paris hospital.

"Yasser Arafat is inside in our hearts — in the hearts of the real nation of Palestine," said Amar Muheisen, 22, from Gaza City as he beat his chest with his fists. "Yasser Arafat will never die."

Palestinians huddled around radios on street corners as loudspeakers from mosques amplified verses from the Quran. Loudspeakers mounted on trucks blared Arafat's most famous quotes.

Gunmen fired into the air — some only 500 yards from Jewish settlements. No clashes were reported amid a mood more of grief than outrage.

Children, already out of school for a Muslim holiday, ran through the streets, swept up in the frenzy.

One 14-year old named Ali, who refused to give his last name, wrapped a fist around a photograph of the late leader. "He said we will raise the Palestinian flag in Jerusalem — and we will."