The Imaduwa police say that a cleaning worker who had seen the grenade had informed the Imaduwa police yesterday (19).
The worker who engaged in his work had come across the bomb that had been placed in a plastic container at around 3.30 pm yesterday.
Later, he had informed the Imaduwa Police regarding this.
The police had arrived at the scene and taken the bomb into police custody.
The Police is to brief the Galle Magistrate's Court today (20) and the bomb will be defused, afterwards.
Imaduwa police are conducting further investigations.