The injured were identified as Anusak Sieng-oon and Apichart Polrit, both 22. Anusak was shot as left leg while Apichart at left arm. Witnesses said the motorcycle had Nakhon Sawan licence plate.
The injured and 100 other students of Ramkamhaeng University were marching to residence of prime minister in Soi Nawamin 81.
They were passing Klongchan flat when the attack took place.
Lardprao police chief Pol Col Somsak Bunsaeng said two men on a motorcycle shot the students.
The students started the march at about 8.30pm to the PM's residence to protest his government.
The shooting happened although police have provided safety along the way.