"I commend them for their actions. Obviously, that would have been pretty horrific for those people," Inspector Pears said.
"It was very brave to enter the water and do what they did."
Police legally shot at the animal, which remained in the area after the horror attack for up to 30 minutes, but it is believed the shark was unharmed.
Fisheries officers resumed patrols from 5am on Monday in a bid to find the deadly shark, the department confirmed.
Beaches from Dampier Creek to Coconut Wells, including Cable Beach, remain closed.
The type of shark is not known but is believed to be a tiger shark.
Broome is not believed to have had a fatal shark attack since 1993 when a pearl diver was killed at Roebuck Bay.
Cable Beach, which stretches 22km and is 2000km north of Perth, is one of Western Australia's most popular tourist destinations.
The attack happened during the "off-season", and surf lifesavers finished their patrols at the beach last week.