The head of the US Agency for International Development (USAID) has blamed the Ethiopian government for the shortage of humanitarian aid in the country’s northern region of Tigray.

Samantha Power says food aid in the region will run out this week for the first time since fighting broke out in November last year.

“This shortage is not because food is unavailable” she says “but because the Ethiopian government is obstructing humanitarian aid and personnel, including land convoys and air access”.

Aid trucks have been unable to leave the town of Semera in the neighbouring Afar region, currently the only accessible land route into Tigray.

The UN has separately told the BBC more than 100 aid trucks are stuck on this route.

The breakdown of a scanner at a checkpoint halted the movement of trucks for around five days from 13 August. The UN says the scanner has been repaired but insecurity is now holding back the trucks.

The Ethiopian government has justified searches at checkpoints along the route saying it has a responsibility to “ensure and guarantee security”.