LONDON (Reuters) - British police said on Monday they were conducting an investigation into a car accident in which the Duke of Edinburgh, Prince Philip of Queen Elizabeth II, was driving while driving near a royal estate yesterday.

Buckingham Palace said the prince was unharmed in the incident.

Police said two people in another car were taken to hospital after the accident, a 28-year-old driver suffered knee injuries, and a 45-year-old woman suffered a wrist fracture.

An infant, no more than nine months old, was not harmed.

Prince Philip, 97, was walking from a special road to the Queen's Sandrigham Palace in Norfolk County to a busy road when his Land Rover Freelander hit another, overturned on one side of a truck and badly damaged it.

The results of alcohol tests for drivers were negative, police said.

British media quoted eyewitnesses as saying that Prince Philip appeared to be in shock and asked if all those who had been injured were safe.

Norfolk officials said they would investigate the incident and said it was "not appropriate to predict the cause of the accident until the investigation is over."