Palestinian President Mahmoud Abbas on Wednesday welcomed a decision by French prosecutors to open a murder inquiry into claims the late Yasser Arafat may have been poisoned.

The probe was announced on Tuesday, a month after his widow Suha and daughter Zawra launched legal action in France following reports that experts had found traces of the radioactive substance polonium on Arafat's clothes.

Gaza's Hamas prime minister Ismail Haniya will not attend an upcoming Non-Aligned Movement summit in Tehran, Taher al-Nounou, a spokesman for the Hamas government, said on Sunday.

"The prime minister received a generous invitation from the Iranian president to participate in the NAM summit," he wrote in a statement, adding that Haniya initially "said he might be going but he decided today to apologize."

Palestinian president Mahmoud Abbas will boycott the Non-Aligned Movement summit in Iran if his Islamist rival Ismail Haniya of Hamas attends, a minister told Agence France Presse on Saturday.

"President Abbas will not take part in the Non-Aligned summit if Haniya is present, no matter what form his attendance takes," foreign minister Riyad al-Malki said in Ramallah, headquarters of the Palestinian Authority.

The Hamas premier in Gaza, Ismail Haniya, is to take part in the Non-Aligned Movement summit in Iran next week, a spokesman for the Palestinian Islamist movement said on Saturday.

"Prime minister Ismail Haniya will attend, in accordance with the invitation from Iranian President Mahmoud Ahmadinejad," Taher al-Nunu, a spokesman for the Hamas government in Gaza, said in a statement.

A Swiss radiology lab said Friday it will test the remains of the late Palestinian leader Yasser Arafat for polonium poisoning after receiving the go-ahead from his widow.

The experts from the Lausanne University Hospital Center, which also got the green light from the Palestinian Authority, will travel to the West Bank to take samples from the body, a spokesman for the lab said.

Palestinian leader Mahmoud Abbas is waging "diplomatic terror" against Israel, which is as dangerous as the violent threat posed by Hamas, Israeli Foreign Minister Avigdor Lieberman said on Thursday.

It was his second personal attack on the Palestinian president in days and came after he called for world powers to force elections in the Palestinian Authority in a bid to replace him and revive the stagnant peace process.

Israeli Foreign Minister Avigdor Lieberman has called on the Middle East peacemaking Quartet to force elections on Palestinians in a bid to oust president Mahmoud Abbas and revitalize the dormant peace process.

In a letter sent on Tuesday to the Quartet's top diplomats, a copy of which was obtained by Agence France Presse, Lieberman said that Abbas "apparently is uninterested or unable... to reach an agreement which would bring an end to the conflict."

The Palestinian Authority has condemned the network of smuggling tunnels between Hamas-run Gaza and Egypt as a "threat" to security and lauded Cairo's campaign to seal them.

Speaking a week after a deadly attack which killed 16 Egyptian border police in northern Sinai, Tayeb Abdelrahim, chief of staff to Palestinian President Mahmoud Abbas, expressed full support for Egyptian moves.

Hamas on Friday hailed the meeting between its leader in the Gaza Strip, Ismail Haniya, and Egypt's Islamist President Mohammed Morsi, saying it represented a "turning point" in bilateral relations.

"The meeting between (Prime Minister Ismail Haniya) and the Egyptian president (Mohammed Morsi) constitutes a real turning point in bilateral relations," Haniya's spokesman in Gaza, Taher al-Nunu, said in a statement.

Arab foreign ministers have backed Palestinian plans to seek an upgrade to their status at the United Nations to that of a non-member state, Palestinian officials said.

But no decision was taken on when the application would be made, with the Arab League postponing such a decision until its next meeting in Cairo on September 5, Palestinian negotiator Saeb Erakat told Agence France Presse late on Sunday.