The explosion happened around 8:45 am local time (0145 GMT) at the compound in Medan on Sumatra island during morning roll call.
"We suspect this is a suicide bombing with one attacker killed," national police spokesperson Dedi Prasetyo told reporters in Jakarta.
He said at least six people were wounded, including four officers and two civilians, but that their injuries were not severe.
An AFP reporter at the scene saw a body lying on the ground outside the station.
Suicide bomber kills 63, injures over 180 at Kabul wedding
The motive for the attack was not immediately known.
In August, authorities shot and arrested a militant who attacked officers at a station in Indonesia's second-biggest city Surabaya, while in June another was seriously wounded when he tried to blow himself up outside a police building on Java island.
Last month, the country's leader Joko Widodo ordered beefed-up security measures after two militants from an Islamic State-linked terror group stabbed his chief security minister. He survived the attack.
The pair were later identified as members of Jamaah Ansharut Daulah (JAD), an extremist network loyal to IS and responsible for several previous attacks - including deadly suicide bombings at churches in Surabaya last year.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ