US and Iranian men released in prisoner swap

The United States and Iran have carried out a rare prisoner swap, in spite of heightened tensions between them.

Also in the programme: Scientists have warned that climate change and pollution are driving oxygen out of the oceans and Iraq has seen one of the worst flare-ups in weeks of anti-government protests.

(Photo: Xiyue Wang with his wife and their son before he was detained in Iran, Aug 2016. Credit: Reuters)