The government announced a list of the country's dirtiest cities for the first time on Friday in a bid to encourage municipal administrations to clean up their acts, and their heavily polluted urban areas.

Previous governments had only made the names of the cleanest cities public.

Depok and Tangerang -- both in West Java -- and the South Sumatra capital of Palembang were named the dirtiest metropolitan cities in the archipelago, while Bandarlampung in Lampung, Batam in Riau Islands, and Bogor -- also in West Java, were listed as the most polluted "big cities".

The list was announced by the State Ministry of Environment prior to the national Adipura environmental award ceremony on Friday evening.

Deputy to the State Minister of Environment for pollution control Gempur Adnan said the move was to encourage regional administrations and residents to clean up their cities and make them green and livable.

The exposure was also intended as a warning to local administrations. However, the government had no plan to penalize the dirtiest cities.

"Clean and green cities. That's what we want in Indonesia," Gempur said.

The dirtiest cities were selected from 365 of 440 regencies and municipalities across Indonesia. Those that were not environmentally examined were generally isolated and had few inhabitants.

During the Friday evening ceremony, the government presented the Adipura awards to the four cleanest cities listed for 2005 -- Pekanbaru, Central Jakarta, Jepara and Bangli.

Guntur said the environmental ministry was also monitoring the top eight cities already nominated as the cleanest cities for 2006. The eight nominees are Padang, Arga Makmur, Semarang, Lumajang, Bangli, Tabanan, Gorontalo and Kolaka.

"The nominees will be awarded the Adipura award next year if they continue to perform well," he said.

The ministry also awarded 23 companies that had complied with regulations to prevent water and air pollution and manage toxic waste.

Among the winners were Riau Andalan Pulp and Paper, Astra Daihatsu Motors, Toyota Motor Manufacturers, Pertamina, Medco Energy and Newmont Nusa Tenggara. The ministry has taken Newmont Minahasa Raya to court over claims that it polluted Buyat Bay in Central Sulawesi with mine tailings.

Ministry deputy for toxic waste management Yanuardi Rasudin, said his office has decided to sue only five companies for failing to comply with pollution regulations.

The five were Naintex in Bandung, Kertas Bekasi Teguh in Bekasi, Kertas Blabag in Magelang, Jatim Taman Steel MFG in Sidoarjo, and Inti General Jaya Steel in Semarang.

Yanuardi said these firms had been environmentally blacklisted for two consecutive years.

"They were already given time to improve their environmental performance, but failed to do so. Therefore, we will soon sue them for polluting the country," he said.

State Minister for the Environment Rachmat Witoelar had earlier said he would file lawsuits against the blacklisted companies by the end of this year.

According to data from Rachmat's office, there were at least 72 private and state-owned companies on the blacklist.