Canberra, Feb 18 (IANS): Australian national park rangers on Saturday issued a "major" warning for tourists to be careful after catching a large saltwater crocodile.

Rangers in the Northern Territory (NT) pulled the 3.7-metre crocodile out of a baited trap in a gorge in the Nitmiluk National Park (NNP), only 30 km from Katherine, one of the territory's most popular tourist attractions, Xinhua news agency reported.

It was the sixth saltwater crocodile caught in the gorge since 2009 and was in the average size range, Andrew McPhee, acting district ranger for the NNP said.

"He's big enough to cause problems," McPhee told the Australian Broadcasting Corporation on Saturday.

The NT has experienced a substantial wet season which has caused river levels to rise, creating perfect conditions for the lethal predators to navigate their way into waterways.

"You always know at this time of year when the river rises, especially when it starts to settle and slow down, it makes it an easy path for any size saltwater crocodile to move up from downstream into the gorge system,"McPhee said.

"We've probably been more surprised in the last few years that we haven't caught any."

Despite being closed during the wet season, some tourists still manage to enter the gorge system to canoe or swim.

Once the wet season finished, rangers spend up to a month surveying the area to ensure it is safe to re-open.