BEIJING - Chinese parents whose children were sickened after drinking contaminated milk pushed the government for greater accountability and compensation Friday, a day after a court handed down two death penalties and long prison terms for 19 other defendants.

Milk formula laced with the industrial chemical melamine has been blamed for causing the deaths of at least six infants and sickening nearly 300,000 others with kidney stones and other problems.

Zhao Lianhai, who has rallied families through a Web site he created that details the crisis, said Friday that he and three other parents were presenting a petition to the Ministry of Health.

The petition, signed by some 550 parents, calls for free medical care and follow-up services for all victims, reimbursement for treatment already paid for, and further research into the long-term health effects of melamine among other demands.

"Children are the future of every family, and moreover, they are the future of this country," the petition said. "As consumers, we have been greatly damaged."

Jiang Yaling, a parent from Guizhou, said the group held a meeting with several Health Ministry officials on Friday. She said the officials pledged to "respect our petition" and process it quickly.

"It's not a matter of what the officials say to us, but it's a matter of what they do. If these demands are not met, my child could have a life span of only 10 years. What kind of life is that? My child is my everything," Jiang said.

The Health Ministry did not immediately respond to a faxed list of questions.

Jiang said the group also planned to submit the same petition to the China Dairy Association and China's food safety regulators later in the day.

The 22 dairy companies involved in the scandal have proposed a 1.1 billion yuan (US$160 million) compensation plan. Families whose children died would receive 200,000 yuan ($29,000), while others would receive 30,000 yuan ($4,380) for serious cases of kidney stones and 2,000 yuan ($290) for less severe cases.

However, many parents have rejected the compensation payments as inadequate and complained that the plan did not have families' input.

On Thursday, 21 defendants blamed in the milk scandal were sentenced, including the former general manager and chairwoman of Sanlu Group Co., the dairy at the center of the scandal.

Tian Wenhua, 66, the highest-ranking executive charged in the food safety crisis, was given life imprisonment while three other company executives got sentences between five and 15 years.

Tian, who pleaded guilty to charges of producing and selling fake or substandard products, testified in court that she knew of problems with her company's products for months before informing the authorities.

Investigations showed that middlemen who sold milk to dairy companies including Sanlu were watering down raw milk, then mixing in melamine to make it appear to have a higher protein content.

One of those middlemen, Geng Jinping, who supplied hundreds of tons of melamine-tainted milk to Sanlu, was sentenced to death. Also condemned was Zhang Yujun, who ran a workshop that produced melamine-tainted powder branded as protein powder.