The founder and CEO of Facebook, Mark Zuckerberg, has been questioned by senators over the misuse of personal data. Also in the programme: the twentieth anniversary of the Good Friday agreement that ended decades of violence in Northern Ireland. Picture: Facebook CEO Mark Zuckerberg arrives to testify before a joint hearing of the US Senate Commerce, Science and Transportation Committee and Senate Judiciary Committee on Capitol Hill. Credit: AFP/Getty Images.

Russia says it wants international inspectors to visit the site of a suspected chlorine gas attack in Syria. But it says no chemical weapons were used there, and has rejected a US resolution that would set up an inquiry into who carried out the alleged attack. Also in the programme: President Xi promises to open up sectors of its economy to greater international competition and; Africa's overlooked scientists get their own journal to raise their profile. Picture: US President Donald Trump attends a meeting with senior military leaders. Credit: Getty Images.

The United Nations Security Council holds an emergency meeting following the reported gas attack on the formerly rebel-held town of Douma in Syria. President Trump strongly condemned the attacks and states that military action against President Bashar al Assad’s regime is “not off the table”. Also on the programme: The fairness of Sunday’s elections in Hungary is put into question by some international monitors; and twenty years since the Good Friday Agreement. (Image: President Trump speaks with the media before a meeting with his cabinet in the White House on 9th April 2018 in Washington DC. Credit: Jim Lo Scalzo-Pool/Getty Images)

Deadly attack on a Syrian military airbase after alleged chemical attack in formerly rebel-held town of Douma. Syria and Russia accuse Israel. There's no comment from Israel. Also in the programme: EU's reaction to Hungary's Prime Minister's re-election; and John Bolton's first week as national security adviser. (Photo: Map of Syria. Credit: BBC)

President Trump says in a tweet there will be a "big price to pay" for the suspected chemical weapons attack on the Syrian town of Douma, as doctors describe treating victims. Also in the programme: the cost of wasted fruit in India, and how a composer turned the sounds of Philadelphia into a piece of music. Photo: A child treated being treated after a suspected chemical weapons attack in Syria. Credit: White Helmets

There's been widespread international condemnation of a suspected chemical attack in Syria which killed scores of people in a rebel-held enclave of Eastern Ghouta. Also in the programme: Hungary's nationalist Prime Minister seeks a third consecutive terms in elections; and a history of US trade wars. (Photo: Pro-Syrian regime forces are seen as they advance towards the town of Douma. Credit: AFP/Getty Images)