They arrived in Aceh province on Sumatra island in a rickety wooden boat, according to a local official, who said he thought the men were the persecuted Muslim Rohingya.
“We can’t communicate with them because they don’t speak Indonesian, Acehnese, or English. So we don’t know much about them,” said Iswandi, the head of Idi Rayeuk district where they arrived, who like many Indonesians goes by one name.
It is not known where the group, aged between around 20 to 40, set off from.
However, in recent weeks authorities in both Myanmar and Bangladesh, where around a million of the Muslim refugees are living in camps, have stopped boats of fleeing Rohingya migrants headed mainly for Malaysia.
It has been rare for Rohingya migrants to attempt the sea routes south since Thai authorities clamped down on regional trafficking networks in 2015, sparking a crisis across Southeast Asia as large numbers were abandoned at sea.
That year, hundreds of Rohingya came ashore in Aceh, where they were welcomed in the staunchly conservative Islamic province.
But there have been concerns the desperate community might start taking to the high seas again after mainly Buddhist Myanmar launched a new military crackdown last year that forced about 700,000 members of the Muslim minority to flee to Bangladesh.
In April, about 80 Rohingya in a wooden boat landed in Aceh just weeks after dozens more arrived in neighbouring Malaysia.
Indonesia tends to accept asylum seekers but they are usually barred from working and often spend years in immigration centres.