BBC News with David Austin

Protests have continued in Brazil with demonstrators clashing with police ahead of an international football match in the north-eastern city of Fortaleza. Skirmishes began when police stopped a largely peaceful demonstration approaching Fortaleza's new stadium before the match between Brazil and Mexico. Leonardo Rocha reports.

Skirmishes began when police stopped a march on the road towards the newly-built Arena Castelao. Brazil has been swept by a wave of protests against bad governance with demonstrators criticizing the high costs of preparations for the next year's World Cup and demanding more investment on education, health and transport. The head of Fifa, the world's footballing authority, Sepp Blatter, said demonstrators should stop using a football competition to have their demands heard.

President Obama has called for intensified efforts to limit the spread of nuclear weapons. In a major speech at the Brandenburg Gate in Berlin, he said he wanted to cut America's own arsenal.

"After a comprehensive review, I've determined that we can ensure the security of America and our allies and maintain a strong and credible strategic deterrent while reducing our deployed strategic nuclear weapons by up to 1/3, and I intend to seek negotiated cuts with Russia to move beyond Cold War nuclear postures.”

Russia's deputy prime minister said Moscow could not take Mr Obama's proposal seriously while the United States was developing its own missile defence system.

Some of the tension surrounding the opening of an Afghan Taliban office in the Gulf state of Qatar appeared to have been defused by an intervention by the US Secretary of State John Kerry. A spokesman for the Afghan President Hamid Karzai told the BBC that Mr Kerry reassured him that the United States would maintain assurances given in writing by President Obama that the Qatar office would not be used by the Taliban as a de facto embassy. Lyse Doucet reports.

President Karzai has long been deeply suspicious of any effort to undermine his government's role in any talks. The sight of a Taliban flag on the new office in Qatar and a sign the Islamic Emirate of Afghanistan confirmed his fear that the Taliban would present themselves as a government-in-waiting. The president suspended bilateral security talks with the US and a trip to Qatar by his own delegation. But a telephone call from US Secretary of State John Kerry has defused tension, at least on this issue. The flag and sign are said to have been removed. President Karzai's spokesman told me the Afghan leader wants to get the wheels moving again.

The UN Secretary General Ban Ki-moon says he is outraged by the Islamist militant attack on the main UN compound in the Somali capital Mogadishu. In one of the most serious attacks on the UN in Somalia for years, at least four foreign UN security staff and four local guards were killed along with a number of civilians and militants.

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Russian officials say a fire at a military arms depot which started with a series of explosions more than 24 hours ago is still blazing. They finally hoped to extinguish it by dumping massive amounts of water from the air. The depot, 1,000km southeast of Moscow, housed some 18 million shells as well as small arms ammunition.

The authorities in the United Arab Emirates have charged 30 nationals and Egyptians of plotting to overthrow the government. The suspects include doctors, engineers and university professors. Prosecutors say the group had set up a branch of the Muslim Brotherhood, which came to power in Egypt after a popular uprising in 2011. Rights activists accused the government of stifling free speech.

Italy's former Prime Minister Silvio Berlusconi has suffered a setback in his attempt to overturn a jail sentence for tax evasion. Alan Johnston reports from Rome.

Mr Berlusconi's lawyers say his trial was mishandled that it should have been held up on one particular day because he was busy with crucial government affairs and couldn't attend. His lawyers said that consequently a retrial was needed. But this argument has now been lost and the case will proceed as planned. It will in the autumn go before the Supreme Court for a final ruling. If Berlusconi's lawyers can't get the verdict struck down then, his four-year jail sentence will stand, although, given his age, he’ll be extremely unlikely to actually be jailed. He would though be barred from public office.

And the Italian fashion designers Domenico Dolce and Stefano Gabbana have been given jail terms of 20 months each on tax evasion charges. A court in Milan found that Dolce and Gabbana had cheated the Italian state of hundreds of millions of dollars in tax by setting up a show company abroad. Their lawyers say they will appeal.

Those are the latest stories from BBC News.