New Delhi: Days after a low-intensity blast took place near the Israeli embassy, Delhi Police have registered an FIR against "unknown" persons, officials said today.

The FIR has been registered under Section 3 (punishment for causing an explosion likely to endanger life or property) of the Explosive Substances Act at Tughlak Road police station based on a complaint lodged by a police officer, they said.

The blast occurred on Tuesday evening in the area between the boundary walls of a house on plot number 4 -- Nanda's House -- and the Central Hindi Training Institute on plot number 2A on Prithviraj Road. The area has bushes, plants and trees and no CCTV camera.

It is behind the Israeli embassy on Dr APJ Abdul Kalam Road, running parallel to Prithviraj Road.

No one was injured in the blast. Police had found an "abusive" letter addressed to the Israeli ambassador near the blast site.