I'm Stewart Macintosh with the BBC news. Hello.

The remaining four candidates for the Republican nomination for the US presidency have faced each other in a televised debate in Florida. The frontrunner Donald Trump came under fire for saying that Muslims hate America. He was asked if he thought that was true of all world's 1.6 billion Muslims. “I mean a lot of them. I mean a lot of them.” “Do you want to clarify the comment at all?” “Well you know, I've been watching the debate today and they're talking about radical Islamic terrorism or radical Islam, but I will tell you that something going on that maybe you don't know about and maybe a lot of other people don’t know about. But there is tremendous hatred and I'll stick with exactly what I said.” The debate took place just days before key primaries in Florida and Ohio which both award delegates on a winner-takes-all basis. It was mostly free of the personal attacks that had characterized previous debates.

Laura Bicker has been watching.

“It looked like a Republican debate, but it certainly didn’t sound like one, not what we are used to anyway, no insults, no jokes, this platform saw a more sedate Donald Trump, but he knows he is ahead. For the others, the next week is do or die for their campaign. Ted Cruz who's won seven states is eager for voters to see him as the only credible alternative to Trump. After weeks of chaos, the state was relatively calm. All will be much clearer after the contests next Tuesday.”

People across Japan have bowed their heads in memory of the 18,000 victims of the massive earthquake and tsunami which devastated the country's northeast coast five years ago. Emperor Akihito and Prime Minister Shinzo Abe are leading a ceremony in Tokyo to mark the moment when the earthquake struck. Bells rang and the Tokyo metro came to a halt as a mark of respect. The BBC's RupertWingfield-Hayes is in the coastal town of Rikuzentakata which was nearly destroyed by the tsunami in 2011.

“A prayer for the dead next to a lone pine tree, the only one survived the 2011 tsunami. The town of Rikuzentakata was once famous for its beautiful beach side pine forest. Five years ago it was wiped out along with 80% of this town. More than 18,00 people were killed here. Almost every family lost someone. Now a huge new tsunami wall is being built, more than twice as high as the old one.”

Amnesty International has accused soldiers in South Sudan of deliberately suffocating over 60 men and boys by sealing them in a shipping container in baking hot temperatures last October. The government has denied the attacks took place.

World news from the BBC.

Russia, Egypt and Senegal have strongly objected to a proposal to send home entire contingents of United Nations peacekeepers if they face repeated allegations of sexual exploitation by some of their members. The three countries said this would amount to collective punishment.

The US authorities say that a top Russian official who was found dead in a Washington hotel last year died of blunt force injuries to the head. When Mikhail Lesin's body was discovered in November, his family said he died of a heart attack. Mr. Lesin had been close to President Putin.

The North Korean leader Kim Jong-un has ordered more nuclear tests using the militarized warheads he says the country's scientists have developed. The state media reported that Mr. Kim had issued the instruction while overseeing a ballistic missile launch on Thursday.

The war of words between the US government and Apple has intensified over the computer giant's refusal to create software to unlock an iPhone used by one of the attackers in a mass shooting in December. In court papers, the Justice Department said Apple's stance was corrosive of institutions that safeguard rights.

Peter Bowes reports from Los Angles.

“The Justice Department says Apple has deliberately raised technological barriers to halt the execution of warrant. The FBI wants to gain access to the phone used by one of the two attackers responsible for the shootings in San Bernardino. Prosecutors say there is probable cause to believe that there is evidence of terrorist attack on the phone. Responding, a lawyer for Apple said the court filing was a cheap shot and had a desperate tone. A hearing into the case is scheduled for later this month.”

The Brazilian Anti-doping Agency says the nation's top female sprinter Ana Claudia Lemos has tested positive for an anabolic steroid. Lemos is South America’s record holder in the 100 and 200 meters and one of Brazil's best hopes for an Olympic athletics medal.

BBC news.