Mainland and Hong Kong stocks extended their declines on Friday, posting their steepest weekly losses since April, weighed down by soft domestic economic data and worries over global trade following US President Donald Trump's new tariffs.

In Hong Kong, the benchmark Hang Seng Index dropped 265 points, or 1.07 percent, to end at 24,507 while the Hang Seng China Enterprises index fell 0.88 percent to 8,804.

For the week, the index plummeted 3.47 percent, recording the first weekly loss in a month and dropping by the most since early April.

On the mainland, the benchmark Shanghai Composite Index ended down 0.37 percent to 3,559 while the Shenzhen Component Index closed 0.17 percent lower at 10,991.

The blue-chip CSI300 index lost 0.51 percent.

The ChiNext Index, tracking China's Nasdaq-style board of growth enterprises, lost 0.24 percent to close at 2,322.

For the week, the Shanghai index slipped by 0.94 percent and the CSI300 dropped by 1.75 percent, with both indexes booking their first weekly losses in six and down by the most since early April when Trump first initiated reciprocal tariffs.

"The US deals with other economies will also affect China's trade outlook," economists at ANZ said in a note on Friday.

"If the US fully enforces around 20 percent tariffs and 40 percent transshipment tariffs on Asean, which accounted for 17.8 percent of China's exports in the first half of this year, the supply chain activity in the region will be strained."

China's factory activity contracted in July, both official and private surveys showed, suggesting the economy lost momentum following robust growth in the first half of the year.

"After a more resilient than expected trade environment in the first half of 2025, momentum could soften a bit further in July," said Lynn Song, chief economist for Greater China at ING, noting that market attention will be shifted to trade data due on Thursday for more clues on the health of the broad economy.

Around the region, Tokyo, Sydney, Singapore, Mumbai, and Bangkok were all down.

In Seoul, the Kospi stock index fell 3.9 percent, its biggest daily drop since April 7, as the government's proposal to raise taxes on corporate income and stock investments raised questions from investors over its market reform push. (Agencies)