JAKARTA -- A return of racial tension in Indonesia's Central Kalimantan has prompted 44 ethnic Madurese settlers to flee back their island off East Java, a report said Sunday.

The settlers boarded a boat at the Central Kalimantan port of Sampit that sailed on Friday to Surabaya in East Java, separated by Madura Island by the narrow Madura Strait, the state Antara news Agency said.

The Madurese were from Pematang Kambat village in the fertile Central Kalimantan district of Seruyan, the subdistrict police chief inspector Suwito Hermawan told AFP.

They arrived at Sampit port under tight police guard, he added.

Hermawan said that many other members of the Madurese community in Central Kalimantan had left separately over the past weeks using cargo and passengers ships to Java.

The Madurese had just returned to the province after years of self exile following violent communal ethnic clashes between themselves and the local indigenous Dayak and Malay communities in early 2000.

They returned to lock up their properties or sell them, Hermawan said.

He gave no details on the tension which had returned and forced the Madurese to again leave.

But Antara quoted the head of the police unit in the Kotawaringin Timur district that covers Seruyan, Deny Putro, as saying that villagers and police had found four decapitated Madurese in the district since Thursday.

Decapitation and mutilation have been the hallmark of the ethnic violence between indigenous Dayak tribes and ethnic Madurese in West and Central Kalimantan since 1999.

Putro said that investigations were proceeding but speculated that the Madurese were killed by people who wanted to appropriate their properties which they had left when they fled in 2000.

He said that five people had been arrested over suspected involvement in the murders.

The Madurese, a hardworking but aggressive ethnic group, were the target of violent attacks in West Kalimantan in 1999 and in Central Kalimantan in 2000, which left thousands killed and tens of thousands of refugees.