If you're planning to cross into Tamil Nadu, or out of it, via Attibele today, change your plans. Kannada activists are shutting the inter-state border from 11 a.m. on Monday, blocking traffic moving in either direction. It's a one-day, one-location action, but it's designed to send a message ahead of a much bigger shutdown planned for August 13.The man behind today's move is veteran activist Vatal Nagaraj, who announced the plan at a demonstration in Mysuru on Saturday. No vehicles from Tamil Nadu will be let into Karnataka, he said, and no Karnataka vehicles will be allowed to cross the other way either. It's a full, two-way stop, not a slowdown.Karnataka Bandh TodayNagaraj was direct about how the closure would work: activists will physically prevent movement across Attibele in both directions starting 11 a.m. Commuters, freight operators, and interstate travellers relying on this route should expect to be turned back or delayed rather than waved through with minor holdups.Why Attibele specifically? It's one of the busiest road links between Karnataka and Tamil Nadu, which is exactly why activists picked it as a pressure point. Today's action functions as a preview of what's coming on August 13, when a full statewide bandh is planned.Karnataka Bandh on August 13Today's border shutdown isn't a standalone event, it's a warning shot. The main event is the state-wide bandh on August 13, called over a cluster of Karnataka's long-running grievances: the Mekedatu, Mahadayi, and Kalasa Bandhuri projects among them. Nagaraj claims over 2,000 pro-Kannada organisations are already backing the bandh, with that number expected to climb past 3,000 by the 13th. He's also asked hotel owners in Bengaluru and Mysuru to stay shut that day.Chief Minister D.K. Shivakumar has already appealed to Nagaraj to call off the bandh. That appeal was rejected.Airport Threat Adds To The TensionThe stakes rose further when Nagaraj was asked about Tamil Nadu Chief Minister Vijay Joseph's proposed visit to Karnataka. Nagaraj's response set a hard condition, support for the Mekedatu reservoir project, or stay away."If not, we will close the airport and not allow him to land in Karnataka," Mr. Nagaraj said.Reports of city-wide gridlock or multiple traffic-jam sites specifically on August 10 aren't part of the confirmed details here, the documented action for today is limited to the Attibele crossing. Anyone travelling on that stretch should plan for a shutdown starting 11 a.m.; the wider disruption, if it comes, is being saved for August 13.