New Delhi, India (CNN) -- Indian investigators are probing a Tuesday pre-dawn firing on guards posted at a space research center, authorities said.
The guards at the facility belonging to the Indian Space Research Organization returned fire, but the attackers fled, according to officials.
No officer was injured, said Rohit Katiyar, spokesman for India's Central Industrial Security Force (CISF), which protects the nation's key installations.
Two gunshots were fired at the guards by at least two men, he said. The shooting did not happen in the main building of the space agency, but at one of its centers.
The facility, about 28 miles (45 km) from the southern Indian hi-tech city of Bangalore, was engaged in research on the country's first unmanned moon project, Chandrayaan, he said.
Space scientists called off the 2008 mission last year after losing contact with the lunar orbiter.
The craft had met most of its mission objectives before it was abandoned, space agency officials said.