Chinese experts have defended the construction of a huge waste incinerator in the scenic eastern city of Hangzhou, state media said on Friday, despite weeks of protests by residents who fear the project will add to pollution.

Choking smog blankets many Chinese cities, and environmental degradation, the cost of the country's breakneck economic growth, has earned the ire of an increasingly educated and affluent urban class.

For more than two weeks, thousands of people have protested against the construction in the Yuhang district of Hangzhou, a protester, Wu Yunfeng, told Reuters by telephone, adding that authorities had started work without the consent of residents.

The plant will be the largest of its kind in Asia, the U.S.-based Radio Free Asia service said this week, quoting a resident as saying the incinerator would handle 3,000 metric tons of garbage daily in its initial phase, rising to 8,000 tons later.

Chinese social media websites showed photographs of a gathering of hundreds of protesters watching a man with a loudspeaker. Other images sent to Reuters by Wu showed dozens of marchers wrapped in Chinese flags.

Government officials in Hangzhou, a tourist attraction best known in China for its lake, said they were not familiar with the protests.

But waste incineration technology "is now very mature", the Hangzhou Daily newspaper quoted Zhao Guangjie, chief designer of the new energy engineering program for ChinaUnited Engineering Corporation, as saying.

Zhao, who was invited to speak to the media, cited design standards adopted by Singapore and Kuwait, the newspaper said.

"After the news came out, many people asked me whether it was safe or not," the report quoted Chen Yong, head of the government-run Chinese Academy of Engineering, as saying.

"I would start by asking them what type of standards do you have for construction?" he said. "If the waste incineration plant is going to be spewing stinking air everyday, then I definitely don't agree.

"But if it is built in a 'garden-style', not only would I not oppose it, I'll even help publicize it," he said, without elaborating on the difference.

Hangzhou, capital of prosperous Zhejiang province, has seen its luster dimmed in recent years by a recurrent smog problem.

Late in March, hundreds of residents of the southern town of Maoming staged protests against plans to build a petrochemical plant there, for fear it would contribute to pollution.