Five months after Presidents Obama and Raul Castro announced their intention to improve ties, the former foes on Friday completed a fourth round of negotiations without ironing out enough of the differences that have accumulated over a half-century of estrangement to restore diplomatic relations. 2 Suicide bombing: A suicide bomber killed 19 people during Friday prayers at a Shiite mosque in eastern Saudi Arabia, residents and officials said, raising fresh concern about sectarian strife in the kingdom. The suicide bomber detonated an explosives belt in the mosque in al-Qadaih village, in the Qatif region, according to police. Sectarian tensions are also being fueled by the Saudi-led military campaign in Yemen against the Shiite Houthi rebels. Uber had sought to overturn multiple restrictions placed on it and similar services by a law enacted last year after a series of large and sometimes violent protests by taxi companies seeking to ban the upstart challenger. The walkout came a day after Paris authorities announced that crime against tourists in the French capital had dropped this year thanks to reinforced police presence and video surveillance. British police say the army safely removed an unexploded World War II bomb found near London’s Wembley Stadium.