Some 18 supporters of the National Congress for Timorese Reconstruction party received injuries and two vehicles were damaged in an attack by members of opposition faction Fretilin, according to reports.

Los Palos Police Commander Marcus Sequera said the incident was being investigated and no arrests had been made.

Mari Alkatiri, Secretary-General of Fretilin, told AAP that the police investigation needed to take its course and urged supporters to refrain from violence.

Speaking after the incident, Arao Noe of the Change for Progress Movement (AMP) party, criticized the violence, saying opposition supporters must respect one another and marinating peace.

Timorese voters are set to head to the polls on May 12, the second time in less than ten months after Fretilin-led government collapsed in January, 2018.