A sinkhole the size of a football pitch has opened up on an island off the coast of Queensland, Australia.
The sinkhole is believed to be around 100 metres wide, and has swallowed part of the Jumpinpin beach on North Sandbroke Island.
Surf Life Saving Queensland, the region's beach safety authority, has advised swimmers to stay away.
“There are really strong currents in the water and the sand is quite unstable,” The Guardian reported a spokeswoman as saying.
“North Straddie now believed to be affected by significant coastal erosion from strong tidal changes, after consultation with land managers.”
The area is a popular fishing spot, but Queensland Parks and Wildlife Service (QPWS) said some of the sand was beginning to return with the tide, the Brisbane Times reported.
“It’s an area where the sand is constantly shifting,” QPWS southeast regional director Mick Cubis said.
“Queensland’s coastal sand masses are dynamic environments and change all the time due to wind, tides and waves.”
Sinkholes occur when rock beneath the surface is eroded by water trapped in the rock, dissolving carbon dioxide gas. This process creates a weak acid that breaks down limestone and causes cavities.
The imbalance and weakness in the rock then puts stress on the underlayer, causing the cavity to grow - before collapsing and creating a sinkhole.
A sinkhole opened up in the middle of a busy road in Manchester earlier this year, however no cars or people were injured in the accident.
