Thousands of followers of Shiite cleric Moqtada al-Sadr staged a mass rally in Baghdad on Thursday against U.S. forces, as Iraqi leaders consider asking for an extended American troop presence.

The demonstration comes with just months to go before U.S. forces must withdraw from Iraq, but senior American officials have said they hope Iraqi leaders will ask for troops to stay, while acknowledging the unpopularity of the soldiers.

Italian Prime Minister Silvio Berlusconi on Wednesday dismissed a Libyan claim that an April 30 NATO air strike killed one of strongman Moammar Gadhafi's sons, the ANSA news agency reported.

Berlusconi said the international coalition had no information that 29-year-old Seif al-Arab, Gadhafi's youngest son, was dead, dismissing the report by a Libyan government spokesman as "propaganda".

Heavy clashes between Yemeni tribesmen and elite Republican Guard troops on Wednesday prompted the closure of the capital Sanaa's airport and the diversion of flights, aviation and tribal sources said.

"Sanaa's airport has been shut down and flights have been diverted to the airport of Aden," the southern regional capital, the official said.

Egypt will open the Rafah border crossing on a daily basis starting this weekend in a bid to ease the blockade on the Gaza Strip, the official MENA news agency reported on Wednesday.

Palestinians will now be able to travel through Rafah -- Gaza's only crossing that bypasses Israel -- under entry rules in place before the blockade was tightened in 2007.

U.S. President Barack Obama said Wednesday the possible Palestinian drive for national recognition at the United Nations was a "mistake", in his most direct criticism yet of the campaign.

Obama also urged Israel and the Palestinians to make "wrenching compromise" for a peace deal after a week of acrimony left prospects of a final settlement more distant than ever.

Palestinian leader Mahmoud Abbas on Wednesday slammed a speech by Israel's prime minister and said the Palestinians would seek U.N. recognition if peace talks don't resume.

"Our first choice is negotiations, but if there is no progress before September we will go to the United Nations," Abbas said, criticizing a speech by Israeli premier Benjamin Netanyahu to the U.S. Congress on Tuesday.

Turkey is ready to help any initiative to end Libya's turmoil but has had no contact so far with South Africa's leader on an exit strategy for Moammar Gadhafi, a government official said Wednesday.

"We have had no particular dialogue (with South Africa) so far but it does not mean that we will not have any in the future," the foreign ministry official told Agence France Presse on condition of anonymity.

Tribesmen loyal to a powerful opposition chief have taken control of state news agency Saba in Sanaa, a high-ranking official and witnesses said on Wednesday, as fighting in the Yemeni capital resumed.

Clashes between security forces and Sheikh Sadiq al-Ahmar's tribesmen broke out in Sanaa on Monday and have left at least 44 people dead, according to an Agence France Presse tally based on reports by medics, the government and tribesmen.

Israeli Prime Minister Benjamin Netanyahu told a cheering U.S. Congress on Tuesday he was willing to make "painful compromises" for peace with the Palestinians, but he offered little concrete to entice Palestinians back to the bargaining table.

By giving such a high-profile speech before overwhelmingly supportive U.S. lawmakers, Netanyahu was able to demonstrate to Israelis that he retains strong backing in the United States despite his frosty relations with President Barack Obama.

The United States on Tuesday announced it is imposing sanctions against seven foreign firms, including Venezuelan, Singaporean, and Israeli companies, as part of efforts to check Iran's nuclear ambitions.

It also imposed sanctions against 16 other foreign firms and individuals, including from China, over trade with Iran, Syria and North Korea in goods or technology that may be used for weapons of mass destruction or missiles.