Unidentified assailants have thrown stones at a vehicle carrying Democratic Party (PD) supporters on a campaign tour of the Liquiga district west of the East Timorese capital.

The incident, which took place early Monday evening, left one car window smashed but no-one hurt and was only reported to police on Tuesday.

A police source told Lusa that an investigation was under way into the "isolated act". Authorities were not ruling out any motive for the attack, he said, while emphasizing that the current election campaign has taken place in a climate of calm, with "zero" politically motivated incidents.

East Timorese voters will on August 30 elect the 88 members of a Constituent Assembly whose main task will be to draw up the future national constitution. Sixteen political parties are contesting the ballot.