LUSAKA (Reuters) - Zambian President Levy Mwanawasa on Tuesday praised China's role in his country but told investors from the Asian economic giant to improve its treatment of local workers in the key copper mining sector.

Mwanawasa reiterated his government's support for China, but said he expected the Chinese not to "disadvantage" Zambians.

Mwanawasa said when he met Chinese investors late on Tuesday that some Zambians were "maliciously magnifying" recent accidents at Chinese-run firms in the mineral-rich southern African country even when such accidents occurred worldwide.

"I want to assure you that we will continue supporting your investments in Zambia. But when incidents of Zambians being disadvantaged come to the fore, we will find it difficult to defend your record," Mwanawasa told Luo Tao, the head of China Nonferrous Metal Mining Group Company Limited (CNMC).

The CNMC owns NFC Africa, which operates the Chambishi copper mines, where Chinese managers shot six miners last year during a protest over poor pay and working conditions.

The managers were never prosecuted.

Mwanawasa said Zambia-China economic relations were growing because Chinese investments had no strings attached, lashing out at Western countries, which have criticized the trend.

"I have said this before and I repeat, 'leave us alone,' we know what is good for us. We have seen them (Chinese) helping us in development efforts. My message is we are not adult infants who cannot think," Mwanawasa said.

Mwanawasa said he was happy with assurances by CNMC to adhere to Zambian labour laws and safety standards at Chambishi mine, adding there has not been any accident at the mine in the last 15 months.

"This is commendable (and) I do hope that other Chinese companies will follow suit," Mwanawasa added.

In 2005, a blast Zambians have blamed on negligence by the Chinese killed 50 people at a plant which supplied explosives to Chambishi.

Luo was due to inspect mining projects in Chambishi, 400 km (248.54 miles) north of Lusaka, where China plans to invest $900 million in copper production and smelting and other manufacturing projects.

Zambian authorities have created economic zones, where Chinese firms will be exempted from paying customs duties on imported equipment and machinery and enjoy other tax breaks.

Officials say Chinese firms will create 60,000 jobs in Chambishi when Chinese firms begin to operate there from 2008.