CAIRO (AP) — Egypt’s foreign currency reserves dropped slightly again last month, the Egyptian central bank said Thursday, part of a two-year downward trend to a critical level that imperils imports of vital goods like food and fuel.

The $13.4 billion level at the end of March was just below the February figure of $13.5 billion, representing a smaller drop than previous months. The nation’s reserves have fallen sharply from $36 billion since the popular uprising in 2011 that ousted President Hosni Mubarak. Constant unrest since then, accompanied by frequent violence, has frightened off tourists and potential investors, cutting deeply into Egypt’s foreign currency income.