The families of three Australians among seven mine workers kidnapped after their driver was shot dead in Nigeria are facing an anxious wait for news as their ordeal stretches into the third day.

The workers, employed by Perth-based engineering company Macmahon, were attacked by about 30 militants near Calabar, around 600 kilometres south of the capital Abuja.

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The four-car convoy was set upon early Wednesday morning, and an eye witness reported seeing the victims bundled into a boat.

Australian diplomats in West Africa are working with Nigerian authorities but it is still not clear if the men who carried out the abduction have made any demands.

Criminal gangs are active in the oil producing Niger Delta, and it’s not uncommon for foreign workers to be taken and later released after a ransom payment.

Unofficially, some European countries will pay ransoms, but it is the policy of Australia and New Zealand not to pay to secure the release of citizens.

Macmahon has suspended trading, and issued a short statement confirming the death of one of their employees.

“The employees who were abducted in the incident include three Australians, two Nigerians, a New Zealander and a South African,” a statement released by the company said.

“We are working to ensure the safe return of all the men involved and are in communication with their families.

“Macmahon is providing support to the men’s families and we ask the media to respect their privacy at this time.

“Counselling has also been made available for all Macmahon employees and their families.”

Two of those kidnapped managed to flee, said Irene Ugbo, a spokeswoman for Cross River State police. She did not know the nationality of the workers still being held.

The kidnappers were yet to contact police, she said.

Foreign Minister Julie Bishop said yesterday the Australian Government was working hard with Nigerian authorities to secure the Australians’ release.