"Until late last night, police were still combing the area to assure there would be no more potential sources of blasts there," the chief security minister said here on Sunday.
He said based on the report he received from Beji Police Precinct on Saturday night, there were three victims who suffered from serious and minor injuries.
"Police are still investigating the blast in Beji, Depok (West Java, near Jakarta). Police have to work carefully and may not be careless," Djoko said.
The coordinating minister for political, legal and security affairs also called on the local residents to increase vigilance and to take care for houses in their surroundings.
"Just report any suspicions (to police). It is better to prevent (an incident from taking place) than being late (in taking action)," the minister said.
It was earlier reported that President Susilo Bambang Yudhoyono has instructed police to investigate the explosion.
The president who is in Russia to attend the Asia Pacific Economic Cooperation (APEC) meeting said on Sunday he had received a report about the explosion from Chief Political, Legal and Security Minister Djoko Suyanto.
"The president has received a report from the chief security minister and has instructed the police chief to investigate and arrest the perpetrators," Presidential Spokesman Julian Aldrin Pasha said here on Sunday.
He said that the president asked the police chief to carry out investigation soon to reveal the cause and the motive of the explosion.
"The head of state immediately ordered police to examine the cause of the blast and to hunt the perpetrators," Julian said.