The Asia Pacific security summit called the International Institute for Strategic Studies (IISS) Shangri-La Dialogue 2015 that was held in Singapore was briefly placed on a lockdown after police officials shot a man dead and arrested the man's two companions on suspicion of security breach.

Police officials in Singapore reportedly stopped a car at a checkpoint near the Shangri-La hotel on Sunday morning at 4 A.M. local time and the driver sped off after he was asked to open the car's boot. The car then rammed towards the barricades of the police resulting the police officials to open fire.

The area where the shooting happened had leaders and defense ministers from around the world as it is where the annual Shangri-La Dialogue 2015 was being held. The driver was killed by the officers and his two passengers, both men and also Singaporeans, were taken into custody by the police.

One of the police officers said in a statement that the arrest was drug-related as substances believed to be illegal drugs were found on one of the men who were taken into custody. The checkpoint was required at the said place because of the ongoing Shangri-La Dialogue and it was one of the security measures planned by the police officials.

A police official said in a statement to The Japan Times, "Substances believed to be controlled drugs and an item believed to be a drug-taking utensil were found on the men arrested."

The man who was shot was not identified publicly but is said to be 34 years old.  Also, the driver and one of the passengers was said to be wanted by the authorities due to various run-ins with the law. Singapore is one of the countries that have tough laws regarding drug-related cases but has the lowest crime rates all over the world.

The lockdown did not last for the whole day as the three-day annual summit resumed hours after the shooting. Police investigations are still ongoing regarding the incident and it is said to be an isolated case and not related to the summit.