BBC news with Jerry Smit. The US Republican presidential candidate Donald Trump says he is now unshackled and free to fight for America in the way he sees fit. He was responding to senior Republicans distancing themselves from him following the publication of lewd comments he made about women. In a series of tweets, Mr. Trump said Republicans were coming at him from all sides and their disloyalty was harder to fight than the Democrats. There has been an attack on a Shiah Muslim shrine in the Afghan capital Kabul. At least 14 people are dead. Many more have been taken to local hospitals. The Shrine at Karte Sakhi was packed with people marking Ashura, one of the most important days in the Shiah's calendar. The UN envoy to the Congo Sambo Sidikou has told the Security Council that the Democratic Republic of the Congo is entering a period of extreme instability. He said the country could reach the tipping point into widespread violence very quickly. The White House says president Obama will look at a number of ways of responding to what it believes was Russian hacking of Democratic Party computers. The White House spokesman said the response would be proportionate, but might not be made public. The Obama administration believes Russian hackers may be trying to influence the outcome of November's election. The head of security in the Brazilian state of Rio de Janeiro, Jose Beltrame, has resigned after nearly 10 years in the post. It follows a rising violence in recent weeks. On Monday there was a high-profile clash between police and suspected drug dealers. President Obama, a self-confessed space nerd, has announced new partnerships with private firms to help to get humans to Mars by the 2030s. In a blog for CNN, Mr. Obama said he was excited to reveal work with commercial partners to build new habitats designed to sustain and transport astronauts on long duration space missions. BBC news.