Here's your 10-point cheatsheet to this big story:
After the Mayor's action, the BJP interrupted the counting of votes. The Mayor, however, insisted the result will be declared without the invalid vote.
Soon, the house fell into chaos - councillors from both sides punched, kicked, slapped and pushed one another amid shouting. Some councillors were seen with their kurtas torn. One of them also collapsed.
"The vote is valid. If it is invalid, according to our calculation, the AAP's candidate will win," a BJP councillor, whose shirt button was torn open, told NDTV. Another BJP leader said the Mayor disregarded counting rules as set by the Election Commission.
"In the house of the MCD, the BJP has shown to the country that it's a party of goons. When BJP knew it was losing by a vote, they started attacking people. The first woman Mayor in Delhi had to defend herself to save her life. The men in BJP climbed on the table and threatened the Mayor," AAP MLA Atishi told reporters.
The MCD house was adjourned later. It will meet on Monday. Earlier, members of the ruling AAP and the BJP climbed on tables and shouted slogans against each other in the Municipal Corporation of Delhi (MCD) house. BJP members said they will not allow a recount.
"One side is ready for recounting, while the other side is not. That is why I'm not recounting. The result is being declared without the invalid vote," said Shelly Oberoi, the AAP leader who was elected Mayor earlier this week after over a two-month delay.
At least 242 of the 250 councillors in the AAP-run civic body voted to select six members to the MCD's standing committee, a powerful body that decides how funds are to be used and on what projects.
After she declared one vote invalid, Ms Oberoi came under the firing line of angry BJP councillors, who shouted "you are not in your senses" at her. Some BJP councillors shouted "Jai Shri Ram" and praised Prime Minister Narendra Modi. Their rivals from the AAP shot back, "Aam Aadmi Party zindabad, Arvind Kejriwal zindabad."
Seven candidates are contesting the standing committee election. The AAP nominated Aamil Malik, Raminder Kaur, Mohini Jeenwal and Sarika Chaudhary). The BJP has fielded Kamaljeet Sehrawat and Pankaj Luthra. Independent councillor Gajender Singh Daral, who joined the BJP, is also a candidate.
Today's fight was a big escalation since January, the last time AAP and BJP councillors threw punches at one another when voting was held to elect the Mayor. The Mayor election had to be postponed several times.
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