The Northern Rivers town of Main Arm has experienced a landslide after the region was hit with extreme rain this week.

Main Arm lies in the hills above Mullumbimby and has been cut off since flooding began on Monday.

People across the region are still feared missing and communication has been knocked out, with residents currently living in what has been described as a "black hole".

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The Main Arm corner store has been set up as a command post, where people are gathering to gain access to supplies.