The accused, Afroz, had been allegedly pressuring his wife for a divorce but she was not agreeing, they said.
His mother-in-law was visiting them from Ghazipur when the couple today again got into an argument, they added.
She scolded Afroz for trying to divorce his wife when she was pregnant, following which he attacked her. When his wife intervened, he attacked her too, they said.
Afroz fled from the spot and police are looking for him.
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