Hello, I'm Fiona MacDonald with the BBC news.

The Colombian government and FARC left wing rebels have signed a key agreement in a step towards a definitive peace accord to end half century of conflict.The President Juan Manuel Santos is to address the nation shortly. Natalia Cosoy reports. The agreement focuses on reparations for victims of the more than 50-year long Colombian internal conflict. It also confirmed as special peace jurisdiction will be set up once final and definite agreement is reached. The tribunal will give more lenient sentences for those who confessed to their crimes. It would be for the country's citizens to decide if they approve or reject the final peace deal. But the government and FRAC hope to sign by March 2016. If that happens, it would bring an end to a conflict that has claimed more than 220,000 lives.

The authorities in Los Angeles have defended their decision to close all public schools for the day because of a suspected security threat. A similar threat was received in New York where the authority said it was not credible, the city's police chief for the Los Angeles' closure a significant overreaction. Peter Bowes reports. Officials say they decided to close down the entire public school system out of what they called an abundance of caution after they've received a threat in an email. The authority said they would search every school in the district to make sure they were safe for pupils to return. As that got underway, New York City officials reviewed they had received the same threat, but quickly dismissed it. A member of the House Select Committee on intelligence has since said the threat is believed to be a hoax.

Republicans vying to become their party's chosen candidate for next year's US presidential election have gathered in Las Vegas for their latest televised debate. National security is expected to be a key issue as James Cook reports. Donald Trump will take central stage for this debate reflecting his lead in nationwide polls. Controversial statement he has made on the campaign trial about Mexicans and Muslims are expected to provoke intense discussion. Mr. Trump's suggestion that the United States should suspend all Muslims immigration has drawn strong criticism from most of his fellow presidential hopefuls in the Republican Party. The topic has been given added gravity by the attacks on Paris and the murders of 14 people in California, both of which have been investigated as cases of Islamist terrorism.

Russia and the United States say world powers are meeting New York on Friday to discuss the Syrian crisis and pass a resolution at the UN endorsing the peace process. Russian Foreign Minister Sergei Lavrov promised the two sides would continue to work on contentious issues, but his US counterpart John Kerry said some progress had already been made. World news from the BBC.

The bodies of at least 19 people have been found in the Mexican state of Guerrero where 43 students disappeared last year. Police said the bodies have been thrown into a narrow canyon, 500 meters deep. Police are expected to compare the remains with DNA samples taken from over 600 families searching for missing relatives in the state.

Supporters of the main Shia sect in Nigeria say police have opened fire on protesters demanding the release of their leader who was arrested in lethal military raid at the weekend. The Islamic movement in Nigeria said three people were killed in the northern city of Kaduna, but police have denied it.

President Obama has mounted a strong defense of open immigration policies saying they're the country's oldest tradition and make America unique. Speaking at a naturalization ceremony for new citizens, Mr.Obama said new citizens continuing renewed and revitalized the nation. We don't simply welcome new immigrants. We are born of immigrants. That's who we are. Immigration is our origin story. And for more than two centuries, it's remained at the core of our national character. It's our oldest tradition, it's who we are.

Greece has given a cautious welcome to plans for new European border force. The Greek minister for migration says the proposed border and coast guard would help Greece to defend its borders. But he told BBC all solution to the migration crisis should respect people's dignity and human rights. The European Commission wants to give the new force nearly 3 times budget of its predecessor.

UN member states have been asked to consider who they want to be the next Secretary General. The US ambassador to the UN is encouraging diplomats to put forward women for the job which has been held by a man for 70 years. BBC news.