China's military build-up is concerning regional countries and international observers [AFP]

Since the Ming Dynasty, China's military prowess has been based on its land forces.

At around two and a quarter million, its standing army is still by far the world's largest.

But over the past two decades, the People's Liberation Army Navy has been undergoing rapid modernisation. Some analysts believe it is the biggest shift in the region's power balance since the Second World War.

Estimates vary, but China's navy is at least 250,000 strong including about 56,000 marines. It is thought to be expanding those numbers although the level of training has been called into question.

Nuclear submarines

One of the issues that has concerned China's neighbours, as well as Western countries, is the development of new classes of nuclear submarine - one long-range submarine, and another capable of firing ballistic missiles.

The Chinese government has been on an international naval shopping spree, buying submarines and destroyers from Russia as well as developing and building its own new sophisticated vessels.

But what has really raised eyebrows is China's announcement in March that it intends to build up to six aircraft carriers, commissioning the first in six years.

China says the need for these new sea-going weapons is to expand its domestic defences. What worries many other countries is that submarines and aircraft carriers have historically been used in offensive roles.

Source: Al Jazeera