Saudi-led strikes on Yemeni rebels are set to dominate an Arab summit that will consider forming a joint military force as several countries in the region teeter on the brink of collapse.

For years Arab states had contented themselves with directing proxies in regional struggles.

Tunisia said Thursday that it had arrested 23 suspects in connection with last week's jihadist massacre at the country's national museum.

"Twenty-three suspects including a woman have been arrested as part of a terrorist cell" involved in the attack, Interior Minister Najem Gharsalli told journalists, adding that "80 percent of this cell" had been broken up.

Taiwanese protesters scuffled with police on Thursday ahead of China's launch of a controversial flight route, which they say has been allowed to go ahead despite fears over security risks.

The route over the Taiwan Strait is due to be inaugurated on Sunday, despite a backlash over security concerns.

Costa Rica said Wednesday it has sacked its ambassador to Caracas for breaking the diplomatic service's rule against talking about local politics.

The ambassador had said that he believed Venezuela enjoys wide press freedom -- an opinion not shared by opposition figures and critics who say the government of President Nicolas Maduro restricts media liberties.

Iran's president Thursday appealed to global leaders including Barack Obama as negotiators raced against the clock to agree the outlines of a deal that puts an Iranian nuclear bomb out of reach.

Hassan Rouhani wrote to the American president, U.S. officials confirmed, as well as to the leaders of the five other powers heading efforts to resolve the 12-year standoff over Iran's nuclear program.

In a damning report released Thursday, Amnesty International said Palestinian rocket fire during the 2014 summer war in Gaza had killed more civilians inside the Gaza Strip than inside Israel.

Such deadly attacks on civilians were against international law and constituted "a war crime," it said.

Four people were killed and 20 injured when a passenger bus hit a landmine near a government-controlled town in eastern Ukraine, local officials said Thursday.

The bus had taken a side road in order to avoid a government checkpoint near the town of Artemivsk, some 50 kilometers (30 miles) north of the separatist stronghold of Donetsk, late Wednesday, said Ilia Kiva, a government-loyal deputy police chief in the Donetsk region. 

Saudi air strikes on Shiite rebels in Yemen triggered a furious reaction from regional rival Iran on Thursday, with top officials warning that military action could spill into other countries.

The bombing of the Huthi rebels, who are said to be backed by Iran, came after days in which Yemen was said to be facing civil war.

Turkish police say a bomb explosion outside the office of a pro-Islamic magazine in Istanbul has killed one person and injured three others.

Police said Thursday that the device was placed outside the door of the monthly Adimlar magazine, on the third floor of a building, and exploded late Wednesday when the door was opened. Police identified the victim as 45-year-old Unsal Zor, who wrote for Adimlar, a magazine that is close to a Turkish militant Islamic organization.

Mustaqbal Movment chief and Former Prime Minister Saad Hariri praised on Thursday the “wise and courageous decision” taken by Saudi King Salman to intervene militarily in Yemen as Progressive Socialist Party leader MP Walid Jumblat feared that it would affect the interest of Lebanese in the Gulf.

“The Iranian interference in Sanaa compelled an Arab reaction,” Hariri said in comments to the al-Arabiya Arabic language television station.