London: Tens of thousands of junior doctors across England on Tuesday went on strike for the first time in 40 years over a dispute with the government for better pay and working conditions, in a move which Prime Minister David Cameron warned would cause "real difficulties" to patients.

The National Health Service (NHS) postponed 4,000 routine treatments such as knee and hip operations. The doctors were only providing emergency cover during the 24-hour walkout, which got underway this morning.