The fighting, which included rock-throwing and arson, occurred yesterday between 6.30 and 7pm between two groups of approximately 100 people in the Bairro Pite area of Dili.
The fighting continued this morning between 10 and 11 o'clock in the same area. Four small houses and a vehicle were burned.
Both today and yesterday, Malaysian and Portuguese Formed Police Units along with UNPol and the International Stabilisation Force (ISF) attended and quickly brought the situation under control.
Nobody has been injured and 17 people have been arrested.
The Special Representative of the Secretary General in Timor-Leste, Atul Khare visited the area this morning to talk with residents affected by the violence. He was accompanied by the UNPol Commissioner Rodolfo Tor.
"While the police - with the assistance of the ISF - took control of the situation very quickly I am concerned to see fighting between groups of young people," Mr Khare said.
"People who commit criminal acts will be treated as criminals by the police. Claiming to act out of political motivation following last week's election will not be tolerated" Mr Khare said.
"In the past 24 hours I have told all political leaders in this country that violence justified as political is unacceptable and I have their agreement.
Specifically I have been in contact with the President-Elect, Dr Jose Ramos Horta, the Secretary-General of Fretilin, Dr Mari Alkatiri and the President of the Democratic Party (PD) Fernando Araujo Lasama. They all agreed that any persons committing criminal acts who claim to be party supporters should be put in jail," Mr Khare added.
UNMIT is mandated through Resolution 1704 to "ensure, through the presence of United Nations police, the restoration and maintenance of public security in Timor-Leste through the provision of support to the Timorese national police (PNTL) ... which includes interim law enforcement and public security until PNTL is reconstituted..."
For more information, please call UNMIT Spokesperson Allison Cooper on +670 7230453