Hundreds of people gathered in front of Indonesia's Corruption Eradication Commission (KPK) building on Monday to show their staunch support for the commission following an intrusion by national police into the KPK compound to forcefully arrest a KPK investigator.

Hundreds of people from several parties in the community have been gathering in the KPK compound since Friday afternoon last week when police broke into the KPK building to arrest mid-ranked policeman Novel Baswedan, whom the police headquarters said involved in a murder case in 2004 and an internal legal process against him is underway at the police headquarters.

KPK supporters made human barricade to prevent police from entering the compound and arresting Baswedan who had stayed at the KPK compound since Friday.

Baswedan is a police officer commissioned in the government- sanctioned anti-corruption agency. He is the one tasked by the KPK in the agency's investigation in a major corruption case of Djoko Susilo.

Susilo was charged of costing the state some 200 billion rupiah (about $21 million) in the procurement of equipment used in driving tests during his tenure as the governor of police academy in Semarang, Central Java.

The media and public regarded the intrusion by the police as a "warning" message intended to deter the commission from pursuing other cases implicating the police force

"Our question is why the invasion to the KPK compound occurs when we are conducting investigations against major corruption cases at the moment," Bambang Widjojanto said in an interview with a national TV station on Monday.

Spats between the police and the KPK had occurred several times before. It previously happened in 2009 when the KPK intended to undertake an investigation into a senior police officer for allegedly receiving bribes.

Police wanted the investigation be done internally at police headquarters, but the KPK insisted the investigation be done in the KPK as it involved civilians as well.

State Cabinet Secretary Sudi Silalahi said that President Susilo Bambang Yudhoyono has issued an order to KPK leaders and police chief to settle the problems between them on Monday. The two institutions are the country's essential forces to fight against corruption, and they are expected to work hand in hand in carrying out their tasks, Sudi said.