At least four people have been pushed in front of city subways in less than two years — all of them Asian immigrants.

The latest victim was Wai Kuen Kwok, a 61-year-old immigrant from Hong Kong who was fatally thrown in front of a D train Sunday by a mysterious attacker at the East 167th Street station in the Highbridge section of The Bronx.

Last November, retired garment factory worker and Chinese immigrant Shou Kuan Lin, 72, of China, was pushed in front of an A train by a vagrant in Harlem. He is brain-dead and remains on life support, law-enforcement sources said.

In December 2012, a psychotic woman threw Sunando Sen, 36, a Bangladeshi, in front of a No. 7 train in Woodside, Queens, killing him.

That same month, Ki Suk Han, 58, of South Korea, was shoved in front of a Q train at the 49th Street station in Times Square by a deranged homeless drifter after a clash on the platform, and died.