Around 10-15 Sena activists, including Satish Gawde, the city co-ordinator of the party's transport wing, were having a get-together at a bungalow in Yeoor Hills in Thani in the wee hours of Thursday when the accused barged in at around 3 am and had a quarrel, they said.
After a wordy duel, the accused allegedly beat up the activists. Gawde sustained serious head injuries in the incident and was rushed to hospital. The accused also allegedly robbed Gawde's gold jewellery that he was wearing, estimated to be worth about Rs 1.92 lakh, police said.
A local party corporator present at the spot was also allegedly threatened by the accused, they said.
Later, based on a complaint, an offence was registered against the accused under IPC sections 394 (voluntarily causing hurt in committing robbery) and 34 (acts done by several persons in furtherance of common intention).
Two of the accused have been identified, police said. No arrest has been made so far, they said, adding that a probe was on to find out the reason behind the incident.