Two people have reportedly been arrested for throwing a rock at the Australian cricket team's bus after their T20 victory over India in Guwahati.
A window was shattered but no one was injured in the incident which happened as the team returned to their hotel after an eight-wicket victoryn over India.
Assam Cricket Association secretary Pradip Buragohain said there would be a "thick security cover" for the team's departure to Hyderabad ahead of Friday's series decider.
"We made every attempt to ensure a foolproof security but don't know how this happened. It was near the team hotel and not at the crowded street near the stadium," he said.
"The police have already arrested two persons and are investigating into the matter.
"I can assure that such an incident won't occur in future again."
The rock left a large hole in a window towards the back of the bus. The seat next to the window was unoccupied at the time.
Legspinner Adam Zampa said he was listening to music through headphones when he heard a loud bang.
"It was a pretty scary incident. You never want those things to happen - it was disappointing," Zampa said.
Zampa, who has played two seasons in the IPL, said he had never felt unsafe while touring India.
"The Indian fans are really great. That's one of the reasons why it's so hard to travel here," Zampa said.
"They're so loud and they actually love cricket - they're so passionate about it.
"Guwahati doesn't get much cricket as it is. For one person to do that and spoil that and spoil it for the rest of the Indian fans is pretty disappointing."
Local Indian politician Himanta Biswa Sharma tweeted an apology.
"People of Assam never endorse such behaviour. We will punish the guilty," Sharma said.
The match was the first international in the north-eastern city of Guwahati since 2010.
The smashed window comes a month after a similar incident for the Australians in Bangladesh where a rock broke a window, prompting security to be beefed up.
Authorities believed local children were behind the Bangladesh rock-throwing.