Two persons moving around in a suspicious manner near a key ISRO facility on the outskirts of the city fired at security personnel in the wee hours today after which the guards retaliated but the duo escaped.

ISRO sources said the security personnel challenged the two when they found them moving around in a suspicious manner. The duo fired at them with a small pistol, after which the security guards retaliated. The incident occurred between 3.30 am and 4.00 am, they said.