Perth, Dec 17: Warring captains Virat Kohli and Tim Paine on Monday resumed their verbal duel, forcing on-field umpire Chris Gaffaney to warn both the players on the fourth morning of the second Test between India and Australia. During the 71st over bowled by Jasprit Bumrah, the respective captains were seen exchanging words after Kohli decided to field close to the non-striker and Gaffaney had to step in."You're the one that lost it yesterday. Why are you trying to be cool today?" Paine told Kohli."That's enough, that's enough," Gaffaney interrupted."Come on, play the game. You guys are the captains. Tim, you're the captain."Paine replied: "We're just having a conversation. There's no swearing ... keep your cool Virat."Kohli said something which couldn't be picked up by the microphones.A couple of balls later, the warring duo almost came close to chest bumping when the India skipper walked in front of Paine while he was completing a run.Kohli later appeared to plead his case to square-leg umpire Kumar Dharmasena as Paine and Usman Khawaja continued to extend Australia's second-innings lead."I reckon it's a sign Kohli is starting to lose it," former Test bowler Damien Fleming said.India commentator Sanjay Manjrekar wasn't too pleased with Kohli's behaviour but former Australian skippers Ricky Ponting and Michael Clarke said they had no issue with the verbal exchange between the two captains and that no line has been crossed so far.Tensions had flared-up towards the end of day three with Kohli and Paine exchanging verbal volleys as the game headed for a nail-biting finish.