BBC News with Jerry Smit

The Syrian President Bashar al-Assad has said Russia was fulfilling its contracts to supply arms to Syria regardless the conflict there. But he would not say of Russia had already delivered the sophisticated anti-aircraft system to which Israel objects. He was speaking to a television station run by the Lebanese Shia movement, Hezbollah.

As far as Russia is concerned, we are negotiating with them over many times at weapons, and Russia has agreed with Syria to fulfil these contracts depending on the circumstances. Part of these negotiations has been fulfilled, and we with the Russians are continuing to implement these contracts.

A court in New York has sentenced a man to 25 years in prison for his role in a plot to kill Saudi Arabia's ambassador to the United States. Manssor Arbabsiar pleaded guilty to charges including a conspiracy to commit an act of terrorism. From Washington Ben Wright reports.

Fifty-eight-year-old Manssor Arbabsiar is an Iranian born US citizen who sold second-hand cars in Texas. He told a court in New York last year that the plot to kill Saudi Arabia's ambassador to the United States involved Iranian military officials, a claim strongly denied by Tehran. The plan was to kill the ambassador by planting explosives at a Washington Restaurant. Arbabsiar  travelled to Mexico several times in 2011 to try arrange the assassination attempt. But his contacts with Mexican drug cartel turned out to be an informant for the US government and he was arrested.

The US authorities have intercepted the threatening letter to President Obama similar to those containing traces of ricin which were sent to the Mayor of New York, Michael Bloomberg and his gun control group. From Washington here's David Willis.

The letter sent to Michael Bloomberg in the mayors against illegal guns group that he found it warned against trying to take away peoples' guns are reference to the debate over greater gun control that has been raging here in the United States since the Connecticut school massacre last year. Whoever wrote them warns that he would rather die than give up his weapons. President Obama and Michael Bloomberg have both been leading proponents for tighter gun control laws.

The mother of the remaining suspect in the Boston marathon bombings says her son, Dzhokhar Tsarnaev has recovered enough to walk. Zubeidat Tsarnaeva told the Associated Press that Dzhokhar had assured her that he and his brother who was killed by the police after the bombings were innocent.

Nigerian members of parliament have approved a bill that will make a gay marriage a criminal offence punishable by up to 14 years in prison. The legislation passed by the House Representatives would also make it illegal to register gay clubs and ban public displays of affection by same sex couples.

You're listening to World News from the BBC

The first international football match scheduled in Brazil's national stadium since it was renovated for next year's World Cup final has been suspended by a judge who said it was not safe. The judge has ordered the authorities to produce guarantees that the Maracana stadium is prepared to host Sunday's game between Brazil and England.

Two prominent opposition activists in Russia have denounced next year's Winter Olympics in Sochi as a monstrous scam, saying that half the $50bn spent on them had been stolen. Their reports said nepotism, censorship and absence of fair competition have led to a sharp increase in the cost of the games. Here is Alex Capstick.

A stunning report on the preparations which started from scratch soon after the Sochi, a holiday resort on the Black Sea won the right to host Russia's first Winter Olympics in 2007. In their report, Boris Nemtsov and Leonid Martynyuk said price tag was over inflated and concluded that up to 30bn had been stolen. Their investigation alleges that many of most lucrative projects were not put out to tender, and have reached only the oligarchs and President Putin's cronies. Alex Capstick.

The US space agency NASA has warned that astronauts on any future mission to Mars would be exposed to so much radiation getting there that they probably develop a fatal cancer. The findings come from data gathered by a NASA spaceship, the Curiosity rover. Jonathan Amos reports.

NASA's Curiosity rover measured the radiation falling on it as it cruise through space for eight months to get the red planet. It allows scientists to put some realistic numbers on the risks astronauts would face making the same trip. They will be bombarded with damaging particle from the Sun and from deep space, raising the probability of getting a fatal cancer and developing neurological and eyesight problems. The only real solution, say researchers, is simply to get to Mars and the relative protection of its surface as quickly as possible.