Date: May 25, 2011 Source: Associated Press   Latest developments in Arab world's unrest YEMEN Fighters from Yemen's most powerful tribes fire on government buildings and soldiers retaliate with intense shelling as the uprising against President Ali Abdullah Saleh threatens to become a militia-led revolt after street protests and Arab mediation failed. At least 24 tribesman and 14 pro-Saleh fighters wre killed. The heart of Yemen's capital is turned into a no man's land with heavy gunfire, mortar rounds and apparent artillery fire from government forces. The latest violence further deepens the rifts and suggests Yemen could be stumbling toward a potentially bloody showdown between well-armed tribal militias and pro-Saleh troops. ___ LIBYA NATO launches its most intense bombardment yet against Moammar Gadhafi's stronghold of Tripoli Tuesday, while a senior U.S. diplomat says President Barack Obama is inviting the Libyan rebels' National Transitional Council to open an office in Washington but stopping short of formal recognition. The international community has stepped up airstrikes and diplomatic efforts against the regime in a bid to break a virtual stalemate, with the rebels in the east and Gadhafi maintaining his hold on most of the west. The NATO airstrikes hit in rapid succession within a half-hour time span, setting off more than 20 explosions and sending up plumes of acrid-smelling smoke from an area around Gadhafi's sprawling Bab al-Aziziya compound in central Tripoli. ___ SYRIA The death toll from Syria's crackdown on a nine-week uprising has exceeded 1,000, a prominent human rights group said Tuesday, as the country's opposition called for fresh protests and clearer goals. Syria, one of the most repressive regimes in the Middle East, has for years crushed any sign of public dissent, banning political parties and throwing critics of the regime in jail. Opposing President Bashar Assad's regime is the only common thread running through the various parts of the movement, including human rights activists, economic liberals and religious opponents of Assad's Alawite Muslim minority rule. ___ EGYPT Egypt's ex-President Hosni Mubarak will stand trial on charges of conspiring in the deadly shootings of protesters during the uprising that ousted him, a major step in a country still rattled by protests and demands for justice. The 83-year-old leader and his two sons also are charged with abusing power to amass wealth, enriching associates and accepting bribes. A date has not been set for the trial in criminal court. ___ BAHRAIN An influential Bahraini business group decides to freeze ties with Iran, Iraq and Lebanon in response to what it sees as foreign meddling during Shiite-led protests in the kingdom. The move by the Bahrain Chamber of Commerce and Industry is likely to ratchet up tensions between the small island nation — which ruled by a Sunni monarchy and is home to the U.S. Navy's 5th Fleet — and its heavily Shiite neighbors. Amnesty International, a leading human rights group, is urging Bahrain's king to overturn the death sentences against two people arrested during the protests.