A city court, at Delhi police's request, issued an open arrest warrants against three Iranians on Wednesday.
The men in question, police sources said, played both "direct and indirect roles" in the attack on an Israeli diplomat's wife at central Delhi's Aurangzeb Road on February 13.
"We have established a watertight case now. Raids have been conducted at several locations in the country but the trio is suspected to have escaped," claimed a senior police officer.
Police claimed to have zeroed-in on them after a week of quizzing Syed Ahmad Kazmi, the Indian journalist who was arrested for his alleged involvement in the case.
The accused are suspected to have entered the Capital on tourist visas along with a "larger group of students" and stayed at least at two locations in Delhi.
"There were certain loose ends after Kazmi admitted to his involvement. We will come out with an official statement on the exact circumstances leading to his arrest in a day or two," the officer said.
Sources claimed the police, which has been reproached by NGOs, human rights groups and Kazmi's kin, will break its silence on Friday.