Crocodile in Kakadu National Park
Residents fear crocodiles have entered the town's sewers and drains David Gray/Reuters

Residents in the Australian town of Palmerston, in the Northern Territory, fear crocodiles have entered the town via sewers and drains after a deadly reptile was spotted attacking a bin.

A Palmerston resident alerted the police after spotting a 1m (3ft) long crocodile mauling his rubbish bin. "Police attended the location only to see the croc make a quick escape down the street drain pipe," a police officer told the Northern Territory News on 24 January.

The crocodile has yet to be located. Another one was spotted in December in the nearby city of Darwin. The 1.5m (5ft) long reptile was hit by a car on a busy road.

The presence of the animals in inhabited areas is linked to flooding caused by sustained heavy rains in the area, which have allowed the crocodiles to travel away from their usual habitat.

The crocodile population in the country has increased exponentially since it became a protected species under federal law in 1971. In the Northern Territory alone, in the past four decades the number of crocodiles has increased from 3,000 to an estimated 80,000 to 100,000

Saltwater crocodiles can live up to 70 years and grow throughout their lives, reaching up to seven metres (23 feet). Their record number in national parks has put rangers on high alert as the giant animals attack boats and bite outboard motors and, sometimes, humans too.

Less than a week ago, the body of a man killed by a crocodile was found at the Cahill's Crossing near the World Heritage-listed Kakadu National Park.

"There is a fair bit of water flowing across at the moment due to the rains and it's a notorious area for crocs there," a police spokesman said at the time.

The man's killing the first fatal crocodile attack in Australia since May, when a 46-year-old woman was taken during a late-night swim in the Daintree National Park in Queensland.