CAIRO, Egypt -- The Central Bank of Egypt has reported another fall in net foreign currency reserves, saying they stood at $17.76 billion by the end of November.

The latest figure was posted Sunday on the bank's website. It showed a fall for a third successive month and the first time since July, when Egypt received major Gulf aid pledges, that reserves dipped below the $18 billion mark. However, it is more than $4 billion more than where it stood in the first three months of 2013.

The bank did not say what caused the latest drop, a key indicator in an economy battered by three years of political turmoil. Hardest hit has been tourism, a major foreign currency earner, although the key sector is showing slow signs of recovery.