Kyrgyzstan and Tajikistan are facing an energy crisis as water levels have plummeted at the reservoirs powering their largest hydropower stations, officials said this week.

The two landlocked Central Asian countries are heavily reliant on hydropower. Both use massive Soviet-built hydropower plants for their domestic electricity output.

The water level in the reservoir connected to Tajikistan's Nurek power plant has dropped by 2.47 metres (8.1 feet) over the last year, the state utility firm told AFP on Friday.

The Tajik Ministry of Energy and Water Resources had said on Thursday the situation there was alarming.

In neighbouring Kyrgyzstan, the reservoir feeding Toktogul hydroelectric plant has lost two billion cubic metres (70.6 billion cubic feet) -- around 20 percent -- over the past year, President Sadyr Japarov said earlier this week.

Restaurants in Kyrgyzstan have been ordered since Thursday to close at 10:00 pm and public establishments must switch off lights by 6:00 pm to save power.

Tajik authorities said officials who failed to stop an "irrational" use of electricity would be fired.

Since the collapse of the Soviet Union, both countries have experienced periodic power cuts, especially in winter, despite attempts to renovate ailing energy infrastructure.

Populations in both former Soviet republics have risen significantly in recent decades, putting pressure on utility networks.

Kyrgyzstan and Tajikistan are home to Central Asia's main water reserves, sharing approximately 20,000 glaciers in their mountain ranges.

But droughts and rising temperatures are hindering the regeneration of the glaciers.

To address the chronic lack of energy, both countries are building new power plants which are intended to better utilise and store water.

When completed, the new facilities -- Kambar-Ata in Kyrgyzstan and Rogun in Tajikistan -- may even potentially allow power to be exported to neighbouring countries, Afghanistan and Pakistan.