The explosion occurred in the Providence industrial area in Mahe, the largest island in the Indian Ocean archipelago, and caused huge damage there and to surrounding areas, the presidency said.
"Following an explosion at the CCCL explosives store that has caused massive damage... and major destruction caused by flooding due to heavy rains, the President has declared a State of Emergency for today the 7th December," the statement said.
The statement added that "all schools will be closed" and "only workers in the essential services and persons travelling will be allowed free movement. This is to allow the emergency services to carry out essential work."
"The Seychelles International Airport is still operational and ferry services between islands are operating for visitors," the tourism-dependent country said on its official Visit Seychelles account on X.
A former British colony, the Seychelles is made up of 115 islands and according to 2021 World Bank data is the richest African country as measured by per capita gross domestic product.