"Though we can't call it routine, it is not so unusual either", said a senior ITBP officer.
The first transgression took place on July 15 and the other on July 25.
Amid the stand-off in Doklam, Chinese soldiers transgressed into the disputed territory along the global border with India.
The area is a demilitarised zone as agreed upon between the two countries and the ITBP jawans patrol the region without weapons, they said, adding the jawans perform their duty in a non-combative manner.
The breach took place on the morning of July 25, when some local shepherds were forced to vacate the land by troops of the People's Liberation Army (PLA).
"The Chinese soldiers stayed for about two hours, from 8 am to 10 am", a government official told this newspaper.
India and China are locked in a standoff at the border in Sikkim, the longest between the two countries since the 1962 war. Officials also said the ITBP patrols the Barahoti region in civil dress where Indian shepherds from border villages and people from Tibet graze their animals. Incidents of similar nature have happened in the past but are normally sorted out locally and should not be given undue importance,"government sources said".
The Indian air space was also violated after a PLA helicopter had entered into the Indian air space in Uttarakhand on July 19. There have been several reports threatening escalation of troop movement in various sectors if India does not withdraw from Doklam.
By July 30, officials reported four incursions in the area, forcing the Indo-Tibetan Border Police to rush troops there. Army sources, meanwhile, sought to play down the latest incident, describing the reports of a transgression as "incorrect".
Officials say there have been many such transgressions as both sides have different perceptions of the Line of Actual Control.
Meanwhile, sources said another transgression was reported at Asaphila, in Upper Subansiri district of Arunachal Pradesh, on Sunday.
"We absolutely will not permit any person, any organisation, any political party at any time, in any form to separate any piece of Chinese territory from China", Chinese President Xi Jinping said during a almost one-hour speech in Beijing.