In pictures: China's milk scandal

The discovery that Chinese milk products had been tainted with the industrial chemical melamine came last September. Within days, long queues of worried parents were forming at hospitals.

The Sanlu firm was the first to admit its products were contaminated with melamine, but other firms soon followed.

Across China and around the world massive product recalls began. Here milk is tipped away after recall in Hubei province.

Within weeks the scale of the scandal widened, with revelations of contaminated eggs and animal feed. Meanwhile huge batches of milk were destroyed, like this one in Hubei.

Nevertheless, the most potent source of the toxin remained milk products - and so children remained the worst affected. Hundreds of thousands were made ill.

And six babies died - including nine-month-old twin Li Xiaokai, shown on the right in a photo held by her father.

In late December, the first trials of suspects began - resulting in sentences including the death penalty. Here a production base and manager and driver stand trial.

But many parents remained unsatisfied - some demanding better compensation and others more research into melamine's effects. Observers note their willingness to defy authorities and speak out.

The convictions of several people involved in the scandal will go some way to calming public outrage. But they will come as little solace to the relatives of those who died.