KPK detained Dzulmi Eldin, mayor of Medan city in North Sumatra province, on charges of taking bribes from his own subordinates. He is a member of the Golkar Party of the ruling alliance.
Earlier, six other people had also been arrested during separate raids in the capital of North Sumatra on October 15.
KPK spokesman Febri Diansyah said Dzulmi had allegedly accepted bribes from various offices of the municipal government. Investigators seized IDR 200 million (US$14,100) in cash as evidence during the arrest.
According to KPK data, he reported a personal wealth of IDR 20.39 billion (nearly $1.5 million) in March.
Since October 14, the anti-graft agency has arrested tens of corruption suspects in at least five different cities, including the head of Indramayu district in West Java province, along with some officials in East Kalimantan province and Jakarta capital city.