The UN has announced an inquiry into the bombing of an aid convoy in Syria.

20 people were killed in the attack last week.

It is unclear whether the blast was carried out by Syrian or Russian forces. 

Both Syria and Moscow deny involvement in the bombing - but Russia has released footage which it claims proves that weapons were being transported alongside the humanitarian aid.

UN Secretary General Ban Ki Moon has urged all the parties involved to co-operate after an estimated 100 tons of medical equipment, baby food and winter clothes were destroyed.