"AAP Maharashtra office attacked by NCP goons," AAP said in a tweet.
According to Aam Aadmi Party volunteer Paritosh, the vandals entered the second floor of their office located at Chakala in Andheri and tore up and burnt the poster of AAP leader Arivind Kejriwal.
The vandals threw black ink bottles all over the office and damaged party banners, he said, adding that the attackers also used filthy language and shouted slogans.
"Police had to intervene and take them away," said Paritosh.
Aam Aadmi Party will file an FIR in connection with the attack and also submit with police the CCTV footage at its office, he added.
Police sources said that the group entered the Aam Aadmi Party office at around 2:30 P.M.
Meanwhile, NCP spokesperson Nawab Malik told PTI that they were "seeking the details of the incident".
The alleged attack comes two days after Aam Aadmi Party leader Anjali Damania attacked Maharashtra Deputy Chief Minister Ajit Pawar saying that Mumbaikars were paying high electricity bills due to corruption and the inefficiency of the state power ministry and the distribution companies.
"In the past three years, due to corruption, mismanagement and inefficiency of the state power department, Maharashtra has incurred losses of up to Rs 22,000 crore," the Aam Aadmi Party leader had alleged.