Posters appeared in Kerala's Wayanad district warning Congress leaders Rahul Gandhi and Priyanka Gandhi Vadra of repercussions if they back KC Venugopal for chief minister's post.
While Venugopal has the backing of the majority of the elected Congress MLAs, VD Satheesan has wide support among the party rank and file and key allies.
The posters appeared outside the district Congress committee office in Wayanad and Vadra's MP office in Mukkam in Kozhikode.
CCTV visuals showed a person putting up the posters around 3am on Wednesday, with local Congress workers launching a search to identify the person.
The Congress-led UDF returned to power in Kerala with a decisive mandate last week, winning 102 of the 140 assembly seats.
