Enrico Letta was set to become Italy's new prime minister, after being asked by Giorgio Napolitano, the president, to form a coalition government. The appointment of Mr Letta, formerly deputy leader of the centre-left Democratic Party, could mark the end of two months of parliamentary deadlock. Mr Letta said he would try to ease Europe's austerity policies. Portugal unveiled an ambitious stimulus programme to revive its economy. The government wants to reduce corporation tax, produce incentives to attract more overseas companies, do away with much of the red tape that stops investment and provide cheap financing for smaller firms. The European Commission proposed that membership talks should begin with Serbia after it partly normalised relations with Kosovo. In a breakthrough deal Serbia conceded Kosovo's control of Serb areas in northern Kosovo, though it will not recognise its claim to independence. After 136 hours of debate in parliament and months of demonstrations by both opponents and advocates, French deputies voted to legalise gay marriage and adoption, making France the 14th country to do so. "Marriage for all" was one of François Hollande's campaign promises. CERN, Europe's particle-physics laboratory, announced a new instance of the rare phenomenon of matter-antimatter asymmetry in particles called strange B-mesons. This may help explain the dominance of matter over antimatter in the universe. Golden Colorado Horacio Cartes was elected president in Paraguay. His Colorado Party ruled for six decades until 2008, when it lost to Fernando Lugo, a former priest. Mr Lugo's impeachment last year saw Paraguay ejected from Mercosur, a regional trade group. It is now expected to be readmitted. Police in Canada arrested two suspected terrorists for planning to derail a passenger train. Police say the men had received instructions from elements of al-Qaeda in Iran, though not support from the Iranian government. A court in Brazil convicted 23 police officers for their part in a 1992 prison massacre. The officers were each sentenced to 156 years for the killing of 13 inmates at a prison in São Paulo. In all, 111 prisoners died. Cheap costs borne by workers A clothing factory collapsed in a town near the Bangladeshi capital, Dhaka, killing at least 175 people, injuring over 600 and leaving hundreds missing. The government blamed shoddy construction that violated building codes. The climbing death toll could make it South Asia's worst industrial disaster in 30 years. Japan's prime minister, Shinzo Abe, warned that he would respond with force if any Chinese people attempted to land on disputed islands. His comments came as eight Chinese ships sailed near islands in the East China Sea that both nations claim. South Korea warned North Korea it would face "grave" consequences if it refused to enter talks about reopening the Kaesong industrial park, which is in the North but administered by both countries. Pyongyang shut the park this month in a strikingly belligerent outburst of rage against the West. Clashes in China's Xinjiang region left 21 people dead, including 15 police officers and officials. A government spokesman said a gang "planning terrorist activities" was to blame, but overseas activists from Xinjiang's Uighur ethnic group disputed this. China continued a rescue operation after an earthquake in Sichuan province killed at least 188 people. Taiwan said a man was in hospital with the H7N9 bird flu virus, the first case to be reported outside mainland China where it has killed 22 people since March. And on it goes More than 250 Syrians, many of them civilians, were said to have been killed in fighting between rebels and security forces in the Damascus suburbs of Jdeidat al-Fadl and Jdeidat Artouz. Israel added to British and French evidence that President Bashar Assad's regime in Syria had used chemical weapons against rebels. The Israelis said he probably used sarin, a lethal nerve agent. The American administration, which has repeatedly declared that Syria's use of such weapons would not be tolerated, said it was carrying out its own assessment of the evidence. Three days after local elections were held, and widely boycotted by Iraq's Sunni minority, security forces killed at least 27 Sunni protesters in the town of Hawija. A wave of sectarian bloodletting elsewhere in the country cast doubt on the survival of Nuri al-Maliki's Shia-dominated coalition government. Bahrain blocked a visit by the UN's special rapporteur on torture, saying it was making its own progress in protecting human rights. The Gulf state has been racked by clashes between security forces and democracy campaigners over the past two years, most recently before the start of the Bahrain Grand Prix. A car-bomb exploded outside the French embassy in Libya's capital, Tripoli. It follows several attacks on diplomatic missions in the country since the fall of Muammar Qaddafi a year and a half ago, and was the first big one in the capital. Brothers grim Federal authorities began piecing together the motives of the Boston bombers, Tamerlan and Dzhokhar Tsarnaev. After the police cornered the brothers, Tamerlan was killed in a shoot-out. Following a huge manhunt, Dzhokhar was found and charged with placing explosives at the Boston marathon that killed three people. The brothers moved to the United States a decade ago from the Russian Caucasus. Max Baucus said he would not seek re-election, becoming the sixth Democrat to leave the Senate at the mid-terms. Thirteen female prison officers in Baltimore were charged with colluding with gang members in a state jail. The guards allegedly smuggled phones, pills and other items for the prisoners. Four of them became pregnant after sleeping with the gang's leader; two had his name tattooed on their bodies. Maryland's prison service said it was working to root out corruption and that its jails "have never been safer."