At least three people have died in a block of flats after a major explosion and fire on the island of Jersey in the English Channel.

This was announced by Jersey's Prime Minister Kristina Moore at a press conference on Saturday evening after there had been talk of one dead and around a dozen missing.

A search and rescue operation is ongoing for more people, Moore said.

It was an "unimaginable tragedy" for the island.

The cause of the explosion remained unclear on Saturday.

According to police, the detonation occurred early on Saturday morning in Jersey's capital, Saint Helier, and the three-story building collapsed.

Police Chief Robin Smith spoke of a "protracted" incident that would take "days, maybe weeks" to deal with.

The Channel Island of Jersey is off the French coast.

It is not part of the United Kingdom, but is directly subordinate to the British royal family as a so-called crown estate.