The United Nations envoy to Yemen resigned on Wednesday after four years in the role, as fighting in the country continues to rage on.

Jamal Benomar, a Moroccan diplomat, had been a mediator between various political organisations since 2012 after he brokered a 2011 transition plan following the Arab Spring. Since then the situation in the country has deteriorated with a Saudi-led collation bombing campaign now entering its fourth week.

UN chief Ban Ki-Moon released a statement saying he "greatly appreciates the tireless efforts Mr. Benomar has made over the years to promote consensus and trust on a peaceful way forward in Yemen".

The Colombian government has announced it will resume a bombing campaign against Farc militants, after the death of 10 government soldiers in an attack yesterday.

Colombia’s President Juan Manuel Santos said, "I have ordered the armed forces to lift the suspension of air strikes on Farc positions until further notice."

Syrian government forces used toxic chemicals in barrel bomb attacks between March 16-31 2015, said Human Rights Watch in a statement released on Tuesday.

Calling on the UN Security Council and country members of the Chemical Weapons Convention to “respond strongly,” the Middle East and North Africa director of Human Rights Watch, Nadim Houry, said,

“Syrian authorities appear once again to have shown complete disregard for human suffering by violating the global prohibition against chemical warfare.”

Hundreds of migrants are feared to be dead after a boat attempting to reach Europe capsized off the Libyan coast.

As many as 400 people are thought to have died as the boat sank in the Mediterranean Sea, with the Italian coastguard stating it has rescued 145 people so far. Whilst 9 bodies have been recovered Commander Filippo Marini, an Italian coastguard spokesman, said they had not found any more "survivors or anything else which would indicate more victims".

The International Organisation for Migration (IOM) and the charity Save the Children said those rescued included "several young males, probably minors, among the victims".

The Colombian government claimed that 10 soldiers were killed in an attack by suspected Farc militants, despite a ceasefire being in place between the warring sides.

The attack, in the Farc controlled town of Cauca, also injured 17 soldiers according to government reports, who claimed grenades and explosives were used in the attack.

The Cuban government welcomed the US decision to remove it from a list of state sponsors of terrorism.

Cuba's top diplomat responsible for dealing with the US, said: "The Cuban government recognised the fair decision made by the president of the United States to eliminate Cuba from a list that it never should have been included on, especially considering our country has been the victim of hundreds of acts of terrorism that have cost 3,478 lives and maimed 2,099 citizens."

The US President Barack Obama pledged $200 million of humanitarian aid to Iraq after the Iraqi leader Haider al-Abadi travelled to Washington to request military supplies, reports the BBC.

Mr Abadi, said that US led air-strikes accompanied by increased arms and training had helped curtail Islamic State advances, and added, “we want to see more.”

The Colombian attorney general has announced he is investigating 22 generals for their alleged role in the killing of civilians as part of the country’s “false positives” scandal.

Hundreds of men were allegedly extra-judicially murdered by the Colombian armed forces, which would then pass of their bodies as those of Farc militants or other opposition groups.

Attorney general Eduardo Montealegre announced on Saturday that 22 generals would also be under investigation, with some 800 members of the security forces having been jailed so far. More than 5,000 members of the security forces were implicated in the scandal added Mr Montealegre.

Four Blackwater Worldwide guards have been sentenced to jail for their roles in the murder of 14 Iraqi civilians in 2007.

A life sentence was handed down to one of the men, whilst the other three were imprisoned for 30 years for their part in the massacre, which also injured 17 Iraqis.

“What happened on September 16, 2007, was nothing short of an atrocity,” said T Patrick Martin, a federal prosecutor. “The United States has shown that regardless of the nationality of the victims, it values justice for all… Even when that means that the American who committed the crime must serve time.”

A US government sentencing memorandum which was filed to the court, said the defendants had “shown no remorse for their actions” adding,

“The crimes here were so horrendous – the massacre and maiming of innocents so heinous – that they outweigh any factors that the defendants may argue form a basis for leniency.”