Twenty gunmen were killed Thursday in clashes between Zaidi Shiite rebels and Sunni Salafists in northern Yemen, a security official said.

Clashes erupted in the morning in the northwestern Hajjah province between rebel gunmen, known as Huthis, and Sunni extremists, the local official told Agence France Presse.

Palestinian President Mahmoud Abbas will on Sunday begin a week-long European tour to Britain, Germany and Russia, his spokesman said on Thursday.

"Abbas will go on Sunday to London, and meet with Prime Minister David Cameron and other British officials on Monday and will brief them on the latest political developments in the region," Nabil Abu Rudeina to Agence France Presse.

Syrian security forces on Thursday shot dead 32 people across the country, activists said, as a rights group said troops opened fire on anti-regime protesters as they tried to approach Arab League monitors in the country’s northwest.

The Local Coordination Committees, the main activist group spurring protests on the ground, said security forces killed 30 civilians and two army deserters in several regions.

Thousands of Yemenis demonstrated on Thursday in several cities voicing their rejection of a Gulf Arab deal to grant President Ali Abdullah Saleh immunity from prosecution, witnesses said.

In the capital Sanaa, protesters marched from Change Square, the focal point of almost a year of anti-Saleh demonstrations, through al-Siteen Street, an Agence France Presse correspondent reported.

Pakistan's President Asif Ali Zardari was in Dubai Thursday for a brief scheduled visit, an aide said, against a backdrop of mounting tension as the government faces new challenges to its rule.

The one-day trip came after a confrontation between Pakistan's civilian leaders and the military over a probe into the government's role in a scandal centered on a mysterious memo that sought US help in curbing the army's power.

A rocket was fired from the Gaza Strip into Israel on Thursday morning and hit without causing any damage or injuries, an Israeli police spokesman said.

"A rocket fired from the Gaza Strip exploded in the Sdot Negev region without causing any injuries or damage," he told Agence France Presse.

British Prime Minister David Cameron is expected Friday in the Saudi capital for talks with King Abdullah, SPA state news agency reported.

Cameron and the Saudi monarch will discuss "bilateral relations, and ways to strengthen them," said SPA, adding without elaborating that the two leaders will also discuss "regional and international issues of common interest."

Israel troops on Thursday demolished an unauthorized settler outpost made up of 10 wooden huts in the southern West Bank, police and the military said.

COGAT spokesman Guy Inbar said forces operating in the early morning had removed "10 illegal structures in Mitzpe Avichai near Kiryat Arba," a settlement just north of the city of Hebron.

Israel's Supreme Court has rejected constitutional challenges to a law that makes it more difficult for Palestinians to get permission to live with their Israeli spouses inside Israel.

The ruling indicates that six judges ruled in favor of maintaining the law late Wednesday. Five were against.

The head of the political arm of Egypt's Muslim Brotherhood on Wednesday hailed U.S.-Egyptian ties during talks with the U.S. State Department's number two, but also said they must be "balanced."

The meeting with U.S. Deputy Secretary of State William Burns at the Cairo headquarters of the Freedom and Justice Party (FJP) came as marathon elections that propelled Islamists to Egypt's center stage wrapped up.