A menagerie of more than 20 pet animals - along with four humans - were rescued from their boat - dubbed Norfolk's Noah's Ark - after it started sinking on a fast-flowing river in the dark.

The drama unfolded in the early hours of Wednesday morning on the River Ouse at King's Lynn.

The 30ft boat - with its unusual crew of dogs, cats, parrots, snakes and a tortoise - is understood to have been heading downriver, towards the Wash, when it got into difficulties.

After the cruiser ran aground near the town's ferry steps off King Street late on Tuesday night, an RNLI hovercraft crew was sent to the scene and helped secure it so it would not drift off when the tide came in.

A tug alongside the cabin cruiser, which is listing heavily (Image: Supplied)

But as the fast-flowing waters began to rise hours later, the vessel started to sink, sparking a major emergency services operation as crews went to the aid of the stricken vessel and those on board.

Locals in the town say they were woken by the sound of dogs barking and described a scene of frantic activity, with "dogs everywhere".

By the time a lifeboat and hovercraft from Hunstanton RNLI arrived, along with a fire service rescue boat and tug, the water was up to the decks of the cruiser.

Hunstanton RNLI hovercraft and lifeboat alongside the cruiser after it sank (Image: Supplied) The crew picked........

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