Police today confirmed that a younger sister of former president Megawati Soekarnoputri was one of seven people arrested yesterday over an alleged plot to topple the government.

Police Public Relations chief Boy Rafli Amar said Rachmawati Soekarnoputri, daughter of Indonesia's first president Soekarno, and the six others were among 10 people arrested in conjunction with the 'Aksi Damai 2 Dis' (Dec 2 Peace Rally) yesterday.

The six others were social activists Kivlan Zein, Adityawarman Thahar, Ratna Sarumpaet, Firza Huzein, Eko Santjojo and Alvin Indra, he said.

All of them were arrested separately, including from their homes and leading hotels, yesterday morning.

Among the three others arrested was popular artiste Ahmad Dhani who was picked up for having allegedly insulted President Jokowi while the two others were taken in for inciting and raising racial issues over social media.

Boy Rafli said seven of those arrested, among them Rachmawati and Ahmad Dhani, had been released as they had offered their cooperation during the investigation.

He also said that all those released were still under investigation and police had evidence of their activities following monitoring for more than six months.

They had joined the rally to protest against Jakarta Governor Basuki Tjahaja Purnama, better known as Ahok, on Nov 4 and the follow-up rally yesterday when hundreds of thousands of protesters gathered in the city and said their Friday
prayers in the grounds of the National Monument.

The crowd for the Friday prayers overflowed onto Jalan Thamrin, Tanah Abang and the routes to the monument.

Ahok had allegedly insulted Islam while campaigning in Seribu Island two months ago.

He is the only non-Muslim among three candidates contesting the post of Jakarta Governor in elections scheduled for February next year. The others are Anies Baswedan and Agus Harimurti Yudhoyono.

Ahok's remarks had angered Muslims in Indonesia and the police will have him prosecuted for having allegedly insulted Islam, an offence that can have him imprisoned for up to six years upon conviction.

Indonesia's police chief Tito Karnavian had advised Muslims to remain calm, saying the police were completing their investigation and would have Ahok prosecuted.