The U.N. agency for Palestinian refugees said Tuesday that 19 of its 20 construction projects in Gaza had ground to a halt because of an Israeli block on building materials.

UNRWA chief Filippo Grandi told donor representatives that since March the agency had "not had any construction projects cleared by the Israeli government, and for the past month, has been unable to import building materials."

Hamas has arrested and tortured dozens of Palestinians in the Gaza Strip over the past few weeks on political grounds, a Palestinian rights group said Wednesday.

The Gaza-based Palestinian Center for Human Rights condemned the "arrest campaign launched by the Internal Security Service (of Hamas) against dozens of persons, including members of (the) Fatah (party) and children."

The bodies of two Hamas militants killed when Israeli troops attacked a border tunnel, burying them inside, were still missing three days after the fighting, Gaza authorities said Sunday.

Four commanders of the Ezzedine al-Qassam Brigades, the military wing of the Palestinian Islamist movement that rules Gaza, were killed late Thursday in clashes sparked by an Israeli raid to destroy a Hamas tunnel from the strip into Israel.

Israel on Tuesday was preparing to release 26 long-serving Palestinian prisoners, the second batch of 104 inmates who are to be freed in line with commitments to U.S.-brokered peace talks.

The release, which is due to take place late on Tuesday night, will see 21 prisoners returned to their homes in the West Bank and the remaining five returning home to the Hamas-run Gaza Strip.

Egypt's closure of tunnels used to smuggle goods into the Gaza strip has caused monthly losses of $230 million (170 million euros) to its economy, a Hamas official said Sunday.

The "closure of the tunnels caused heavy losses to the industry, commerce, agriculture, transport and construction sectors" of around $230 million monthly, said Hatem Oweida, deputy economy minister for the Islamist movement Hamas that governs the strip.

Gaza's Islamist Hamas rulers sentenced a murderer to death on Thursday, the interior ministry said, just weeks after another criminal was hanged in a move that outraged human rights groups

A court in Khan Yunis in the southern Gaza Strip sentenced a man who it did not name to "death by hanging for the murder of Aliyan al-Tilbani" during an armed burglary at a biscuit factory, a statement from public prosecutor Ismail Jaber said.

Israeli troops shot dead a Palestinian militant from the radical Islamic Jihad movement during a gunbattle near the West Bank city of Ramallah on Tuesday, an army spokesman said.

"A wanted Palestinian terrorist was killed this morning in Bilin during a gunfight with the army while he was in a cave," tweeted army spokesman Avichay Adraee in Arabic.

The military wing of Gaza's ruling Hamas said on Monday that it masterminded what Israel called a "terror tunnel" from Gaza into the Jewish state, meant to kidnap Israeli soldiers.

"This tunnel was made by the hand of the fighters of (Izzadine) al-Qassam and they will not sleep in their efforts to hit the occupation and kidnap soldiers," the group's spokesman Abu Obeida told Hamas' al-Aqsa radio.

The Gaza Strip's Hamas prime minister Ismail Haniyeh denied on Saturday reports that the Islamic militant group was involved in fighting in the neighboring Egyptian Sinai or in Syria.

"We did not interfere in the affairs of any country and are not involved in the events or differences or internal conflicts of any country," Haniyeh said.

Israel on Sunday froze the shipment of building materials into Gaza after discovering what is described as a sophisticated "terror tunnel" into the Jewish state from the Palestinian territory, an Israeli defense official said.

"Due to security reasons, (the army) decided to stop for now the transfer of building materials into Gaza," Guy Inbar told Agence France Presse.