India's Ministry of External Affairs (MEA) has condemned the trespassing of and vandalism at the Indian Embassy in Zagreb.
"Under the Vienna Convention, diplomatic premises are inviolable and must be protected," the Indian statement underscored.
It said that the Indian government has strongly taken up the matter with Croatian authorities, both in New Delhi and in Zagreb.
India has demanded that perpetrators behind the illegal and "reprehensible" actions should be brought to justice.
"Such actions also speak of the character and motives of those behind them, and law enforcement authorities everywhere would do well to take note of them," the MEA statement said.
According to a video issued by Pannun, the Indian flag at the Embassy was taken down and a Khalistani flag was briefly raised in its place.
Pannun claimed that the vandalism at the Indian diplomatic premises was aimed at sending a message on "European soil" ahead of European Council President António Luís Santos da Costa and EU Commission President Ursula von der Leyen's participation as Chief Guests at annual Republic Day celebrations in Delhi on 26 January.