"This seems to be an amateurish attempt made by two men with country-made pistols," he told reporters.
Informing that A team will be investigating the matter, the Home Minister said that the CISF, in-charge of the security of ISRO, has been asked to 'another security review' of the area.
Chimabaram said that the preliminary reports reveal that the security guards at the ISRO facility were shot from a distance of 10-15 metres in the early hours by two masked attackers.
"The sentries fired back," he said.
Chidambaram ruled out any danger to the establishment.