BBC News with Julie Candler.

The Secretary General of Nato has accused the Afghan President Hamid Karzai of playing with fire by refusing to sign a security agreement with the United States. It will permit a reduce presence of international troops beyond the end of the Nato-led combat mission which is due to end this year. Anders Fogh Rasmussen also expressed frustration at recent comments made by Mr. Karzai, criticizing aspects of that mission. He said Nato countries expected some signs of gratitude from the Afghan political leadership.

Personally, I have an excellent relationship with President Karzai, but having said that, I also have to say that such statement is something like playing with the fire. Because we should estimate the damaging effect on public and political support for our presence in Afghanistan when people hear such statement.

A priest in the Central African Republic says in the past week at least 75 Christians have been killed in sectarian violence in the town of Buda. He said heavily armed Muslims erected barricades at the entrance and exit to the town before attacking Christians. Thomas Fessy reports.    

Father Cassien Kamatari said he had called French and African Union soldiers for help. He said about 1,500 people have sought refuge in the church in Buda. Clashes broke out last week as the mostly Muslim Seleka militia started to flee to the north. Armed men, reportedly Muslim, killed at least 75 Christians, according to Father Kamatari. Although it seems that Christian militia were involved in the violence, the exact details of these clashes remain unclear.

The US Treasury Secretary has warned that the government could start defaulting on its obligations very soon unless congress lifts its limit on how much money the government can borrow. Jack Lew said Washington will start reaching the debt ceiling on Friday when a current suspension on the debt limit is scheduled to run out. He said the Treasury would then use accounting measures to allow government to keep adding to the debt, but Mr. Lew said this strategy would only work until the end of the month.

A Russian court has detained an environmental activist and critic of the Sochi Winter Olympics. Yevgeny Vitishko will be held for 15 days. Here is Grant Ferrett.  

With just a few days until the opening of the most expensive Games in the history of the Olympics, the Russian authorities appeared to be extremely sensitive to any potential criticism. Yevgeny Vitishko has highlighted what he says the environmental damage caused by the Olympics. He was due to travel to Sochi to present a report when he was arrested and jailed for swearing in public. The human rights group Amnesty International accused Russia of intensifying a campaign of harassment against civil society groups ahead of the Olympics.

World News from the BBC.

The United States and the European Union are in preliminary talks about putting together a financial aid package for Ukraine once a new technical government is formed. US and EU officials said any money would be contingent on a new Ukrainian government pursuing political and economic reforms. Analysts say the move would appear to be an attempt to strengthen Western influence in Kiev. It comes after the Ukrainian President Viktor Yanukovych backed away from closer cooperation with the EU.

Saudis who fight in Syria or elsewhere could be jailed for up to 20 years. Under a new royal decree, Saudis who participate in any conflict abroad face between 3 to 20 years in prison. The decree adds to the same penalties face any Saudis who join or endorse groups classified by the government as terrorist whether at home or abroad. A number of Saudis have joined the fight against President Assad in Syria. Saudi Arabia fears that fighters espousing a jihadist ideology could switch their attention to their homeland.

Officials in the Indian state of Maharastra have ordered an inquiry into reports that stray dogs have been released into the forest threatening the health of tigers in a nearby reserve. It's thought the dogs have been taken far from the city to stop them coming back. It's estimated that there are around 80 tigers in the reserve. Our South Asia editor reports. Anbarasan Ethirajan reports.

A senior forest department official told the BBC that they were first alerted by a conservation group that stray dogs have been released at midnight by some municipal workers in the forest area close to the main tiger reserve. Conservationists say domestic dogs may carry the canine distemper virus which can kill tigers. Reports say 4 tigers have already died because of the virus in other parts of India. Canine distemper virus has seriously affected wild cat populations elsewhere in the world.

BBC News.