Calgary police perform a grid search of the restaurant parking lot Sunday. (CBC)

The victim of a brazen shooting at a Vietnamese restaurant Sunday has been identified as a longtime employee of Canada Post.

Hai Michael “Mikey” Du, 36, died after two gunmen opened fire at Basil Ultimate Pho and Fine Vietnamese Cuisine just after 2 a.m. MT Sunday, hitting four people.

Two other men, in their 30s and 40s, remain in critical condition. A woman later showed up at hospital suffering from a minor gunshot wound.

Canada Post officials tell CBC News Du had worked for them for 18 years.

Police say two people - one wearing a dark-coloured hooded sweatshirt, the other a light-coloured hooded sweatshirt - walked into the restaurant during a private party and began shooting.

At least one of the injured men is suspected of being the intended target of the shooting and associated with a local street gang, while the other victims were struck with stray gunfire, police said.

Du was not known to police. Investigators believe the postal worker was sitting behind the intended target and was likely unintentionally killed.

Around 50 people were inside the restaurant when the shooting occurred.

Only five were still at the scene when police arrived. Several have since come forward to speak with investigators.

Investigators are looking for anyone who saw a white Lexus sedan seen speeding away from the area after the shooting.

Basil is located in the Horizon Industrial Park, next to the community of Whitehorn.