A drunk driver has put a police officer in hospital and injured another after he crashed into their car in Melbourne's north-west.

The two police officers were responding to another accident when the 74-year-man ploughed into their car, which had flashing lights, near the intersection of Main Road East and East Esplanade in St Albans about 10.05pm on Thursday night.

Both police officers suffered minor injuries, with one being taken to a nearby hospital for observation.

The 74-year-old man, who recorded a positive preliminary breath test, was taken the Royal Melbourne Hospital, also for observation.

A police spokeswoman did not have details about the initial accident the officers were responding to, saying only that a car had been driven through a school fence.