Nato troops among 16 dead in Afghanistan attack

A suicide bomber has killed 16 people - including four Nato soldiers - in an attack on the outskirts of Bagram air base in north-eastern Afghanistan.
Ten civilians and two police officers were also reportedly killed in the attack on a clinic near the largest US base in the country.
The attack comes amid tension over a contested presidential election result.
US Secretary of State John Kerry has warned that a failure to accept the result could harm security and aid.