The Sri Lanka suicide bombers had planned an attack on a fourth luxury hotel, but for some reason it never occurred, officials said Tuesday.

Prime Minister Ranil Wickremesinghe revealed the plot on the unnamed luxury hotel without saying why it failed, according to the New York Times.

This man had also checked into the hotel the previous day,” an official source told Agence France-Presse of the terrorist.

The source claimed that hotel staff became suspicious after news broke of the other hotel attacks and the would-be bomber fled the hotel. He was soon tracked to a small inn on the outskirts of the capital Colombo.

He blew himself up when confronted by police, with two bystanders also killed, according to AFP.

That blast at the Tropical Inn opposite Dehiwala Zoo was the seventh on Easter Sunday, following near-simultaneous attacks on three churches and three luxury hotels. An eighth explosion later killed three police officers as they raided a safe house used by members of the cell.

Officials say at least 40 suspects have been arrested over the terror attacks that killed at least 321 and injured 500.

The dead includes 39 foreign nationals, including four Americans.