MATARAM - Indonesia detained 14 Afghan migrants on the southern island of Papakan who were attempting to sail to Australia, an official said Saturday.

The migrants were discovered on the island in West Nusa Tenggara province on Friday night, local seaport operational head Ali, who only uses one name, said.

Officials detained 56 Afghan migrants earlier on Friday after their boat was intercepted in waters near the island.

"We suspect that those 14 Afghan people we have detained on Papakan Island are part of the group we detained earlier," Ali said. "Our suspicion is that the migrants planned to sail to Australia as a group."

The Indonesian Navy's Eastern Fleet suspected that some of the detained migrants were among 74 Afghans who went missing in the country's east in July. Police soon found 15 of the migrants, but the remainders are unaccounted for.

Indonesia is a key staging point for people smugglers bringing Afghans and other nationals for a perilous onward sea journey to Australia.

More than 1,000 migrants from countries including Myanmar, Afghanistan, Iraq, Sri Lanka and Pakistan have been caught in Indonesia since November last year.