Iran nuclear deal: Kerry extends stay as talks overrun
Talks on Iran's nuclear programme will continue until at least Thursday morning, two days after the original deadline, the US says.
US Secretary of State John Kerry has extended his stay to continue negotiations, officials say.
However, a number of foreign ministers have left the talks and China warned compromise was essential, otherwise "all previous efforts will be wasted".
A deal would curb the nuclear programme in return for sanctions relief.
Ben Bland reports,