•Five people have been admitted to hospital and one of those is in intensive care.
•The blast, along with flooding caused by heavy rains, led to a state of emergency being declared, which has now been lifted.
A massive explosion at an industrial zone on Seychelles' main island, Mahé, left the place looking "as if we went through a war", President Wavel Ramkalawan has said.
It had ripped through the area leaving a trail of devastation.
No deaths have been reported so far, but one person is in intensive care.
The blast, along with flooding caused by heavy rains, led to a state of emergency being declared, which has now been lifted.
Earlier on Thursday President Ramkalawan ordered everyone except essential workers to stay at home.
The explosion happened just after 02:00 local time (22:00 GMT Wednesday) at a construction and quarrying company, where explosives were being stored in four containers.
"For the last 10 years there were major concerns about the stock of explosives [being held]," President Ramkalawan is quoted by the Seychelles Nation newspaper as saying.
"Four containers of explosives blew off... My heart is heavy right now and I know many families are being affected. I was shocked to see Providence, Petit Paris and Cascade in such a state. It was as if we went through a war."
Describing the scale of the blast, Seychelles Minister of Fisheries Jean-François Ferrari said: "The explosion was so so big and so loud... that it left a hole 13 metres in the ground... and blasted away windows, doors, roofs of many commercial buildings."
The international airport was also damaged, despite being 4km (2.5 miles) away. Schools are shut and hospitals closed to all but emergency cases.
More than 170 casualties were reported, most with light injuries. Five people have been admitted to hospital and one of those is in intensive care.
The only movement allowed is into and out of the holiday islands. Seychelles' economy is heavily reliant on tourism.
"The Seychelles international Airport is still operational and ferry services between islands are operating for visitors," the country's official account said on X.
Exceptionally heavy rain overnight has caused severe flooding and landslides, adding to pressure on the island's response teams.
Three people died when their homes were destroyed.
The deluge has caused sewage to flow into the ocean and people are being advised not to swim.
President Ramkalawan called the twin disasters a "calamity" for the country and appealed for people to show solidarity to those affected.