Ethiopia’s largest commercial bank is trying to retrieve millions of dollars withdrawn by its customers after an incident it described as a systems glitch.

More than $40m (ÂŁ31m) were reportedly withdrawn from the state-owned Commercial Bank of Ethiopia, or transferred to other banks, when customers found out they could take out more cash than they had in their accounts.

It took several hours before the institution froze all its transactions.

A cyber attack has been ruled out as the cause of the glitch.

Witnesses told the BBC some students in university campuses, where most of the withdrawals were made, have since been detained.