Two dogs have been rescued from a large and growing sinkhole that appeared weeks ago in farmland in central Mexico.

The sinkhole’s crater has grown larger than a football field and begun swallowing a house since it appeared with a loud crack one Saturday.

The government of the central state of Puebla said late on Thursday (local time) it had managed to pull the dogs out of the sinkhole, after emotional requests from animal lovers to rescue them.

They had been trapped for about four days on a ledge on the sheer sides of the hole dropping 15 metres to water.

Loose soil at the edges of the sinkhole keeps collapsing into the water at the bottom of the pit, so for days it was considered too dangerous to try to rescue the dog.

But on Thursday a firefighter descended into the pit, partly by using a ladder to steady the soil on the edge.

His colleagues were seen standing farther back using ropes and a pulley system to haul up cages carrying the two dogs.

The state government distributed photos of the dogs, named Spay and Spike, looking alert and in the care of veterinarians.

The dogs were apparently playing in the farm field surrounding the sinkhole when they fell in.

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The sinkhole is now over 125 metres across in some places, and might be 45 metres at its deepest point. It is hard to tell, because water fills the crater.

The Mexican government has sent in soldiers to keep people 600 metres away from the edge of the hole.

“It’s a very hard time for us. It hurts, because this is all that we have,” said Magdalena Xalamigua Xopillacle, whose brick and cinderblock house was slowly collapsing into the sinkhole.

“At times we feel sick from so much sadness.”

Another family was also evacuated as the hole expanded.

“We have nothing. We’re not from here. We have no relatives. We’re alone,” Heriberto Sanchez, who is originally from the south-eastern state of Veracruz, said late in May.

Some residents believe the sinkhole is the result of excessive ground water extraction by factories or a water bottling plant in the area.

But the bottom of the hole is filled with water that appears to have strong currents. The national civil defence office said experts think it was caused by something like an underground river.

“It is highly probable that the origin is associated with the presence of subterranean water flows,” the office said.

Authorities have set up metal barriers and police tape to keep onlookers out, and has restricted flying drones over it.

-with AAP