A leading Pakistani human rights activist has been shot dead in Karachi, shortly after hosting an event detailing torture in Balochistan.

Sabeen Mehmud, director of the charity The Second Floor (T2F), was killed as gunmen opened fire on her vehicle leaving a seminar she hosted on torture in Balochistan. Her mother, who was also in the car, was injured in the attack.

The United Nations High Commissioner for Refugees said the situation in Iraq and Syria was “utterly unsustainable” and that unless urgent action was taken “things risk getting even worse".

In an address to the UN Security Council In New York, High Commissioner António Guterres called the situation in the Middle East “a cancer that risks spreading and metastasizing”. “If things continue this way, we could see future developments spin out of control, independently of our will and with increasingly dangerous global consequences," he warned.

"We have to recognize the increasingly protracted nature of this refugee crisis,” added Mr Guterres, as he called for increased humanitarian aid, as well as “stopping the horrific loss of life in the Mediterranean”.

However, Mr Guterres warned that the situation could deteriorate further, saying, “after Iraq became so dramatically engulfed in the Syrian conflict with the attacks on Mosul and Tikrit last year, I do not know where the next disrupting shock will take place.” “I only know that it will come, and that things risk getting even worse," he added.

He was joined by UNHCR Special Envoy Angelina Jolie Pitt, who said “it is time for the Security Council to work as one to end the conflict, and reach a settlement that also brings justice and accountability for the Syrian people."

The final stages of clinical trials of a vaccine against malaria are ongoing, which, if successful, could help immunise millions of children from the disease which can be deadly.

However tests conducted on 16,000 children in Burkina Faso, Gabon, Ghana, Kenya, Malawi, Mozambique and Tanzania, showed that booster doses were not as effective as the initial dose, and immunisation waned over time.

Prof Brian Greenwood, study author and professor of clinical tropical medicine at the London School of Hygiene and Tropical Medicine, said to the BBC he was "a little disappointed" by the results.

"I hoped the vaccine would be more effective, but we were never going to end up with the success seen in measles vaccines with 97% efficacy."

The Indian government placed the philanthropic organisation, the Ford Foundation, on a national securty watch list, due to its past/ funding of an NGO which recently pushed for the prosecution of Prime Minister Narendra Modi over his role in the massacre of Muslims in Gujarat on 2002.

The home affairs ministry on Thursday sent a letter to the Reserve Bank of India, asking the central bank to place the Ford Foundation on a watch list to ensure that the funds it distributes are used "for bona fide welfare activities without compromising on concerns for national interest and security".

The move means the organisation can now only disburse funds after clearance from the home affairs ministry.

The US admitted a counter-terrorism operation conducted in Afghanistan in January killed two hostages, who were detained by al-Qaeda.

Speaking at the White House, President Barack Obama said it was a painful loss he deeply regretted.

Chechen president Ramzan Kadyrov has ordered his troops to fire at Russian security forces, if they do not have permission to be there, after the killing of a man in Grozny by troops from Russia's Stavropol region.

Mr Kadyrov, who took charge of the republic in southern Russia with the support of Moscow in 2007, maintains his own security forces in Chechnya.

The government of the Central African Republic (CAR) voted to create a Special Criminal Court to deal with war time atrocities on Wednesday.

The International Criminal Tribunal for Rwanda (ICTR) held its final hearing on Wednesday, concluding more than 20 years of work indicting those responsible for the 1994 genocide, which saw the deaths of more than 800,000 people.

Based in Tanzania, the ICTR has indicted 93 people throughout its history, becoming the first international tribunal to deliver verdicts in relation to genocide and the first to recognise rape as a means to carrying out genocide, reports the BBC.

As the final hearing concludes, 61 defendants have been convicted and 14 acquitted by the court. Other suspects have been tried by different courts, remain at large or have since died.

The final hearing was an appeal from former women's minister Pauline Nyiramasuhuko, who was the first woman to be found guilty of genocide by an international tribunal, when she was convicted in 2011.

The Japanese prime minister, Shinzo Abe, said Japan felt “deep remorse” at its actions during World War Two, stopping short of the apology demanded by countries affected, including China and Korea.