• Asia-Pacific stocks were mixed on Monday.
• Shares of Chinese tech firms in Hong Kong soared following a Wall Street Journal report that regulators in China are concluding probes on ride-hailing firm Didi and two other U.S.-listed tech companies. 
• China's Caixin Services Purchasing Managers' Index released Monday came in at 41.4, an improvement over April's reading of 36.2 but still in contraction territory.

SINGAPORE — Shares in Asia-Pacific were mixed on Monday, with Chinese stocks leading gains regionally as tech stocks in Hong Kong surged.

Hong Kong's broader Hang Seng index closed 2.71% higher at 21,653.90.

Shares of Chinese tech firms in Hong Kong soared following a Wall Street Journal report that regulators in China are concluding probes on ride-hailing firm Didi and two other U.S.-listed tech companies. Regulators plan to lift a ban on the firms adding new users on their platforms, and allow their apps back on domestic app stores, according to the report.

Shares of Alibaba in Hong Kong gained 5.04% while Meituan jumped 9.93% and Baidu climbed 5.18%. The Hang Seng Tech index gained 4.64% to 4,601.95.

In mainland China, the Shanghai Composite closed 1.28% higher at 3,236.37 while the Shenzhen Component surged 2.664% to 11,938.12.

China's Caixin Services Purchasing Managers' Index released Monday came in at 41.4, better than April's reading of 36.2 but still in contraction territory.

The release comes on the back of last week's official non-manufacturing PMI print of 47.8 for May, an improvement over April's reading of 41.9 but still below the 50 mark that separates expansion from contraction.

PMI readings are sequential and represent month-on-month expansion or contraction.

In Japan, the Nikkei 225 climbed 0.56% on the day to 27,915.89 as shares of Fast Retailing jumped 2.77%. The Topix index advanced 0.31% to 1,939.11.

Australia's S&P/ASX 200 fell 0.45%, finishing the trading day at 7,206.30.

MSCI's broadest index of Asia-Pacific shares outside Japan rose around 0.8%.

JPMorgan Asset Management's Tai Hui said the firm is currently watching signs of U.S. momentum "clearly starting to decelerate" as well as the impact of tighter monetary conditions.

"I think that's where we're monitoring very closely but we're not quite there yet when it comes to [being] bearish on … Asia markets," he told CNBC's "Squawk Box Asia" on Monday.

Markets in South Korea were closed on Monday for a holiday.

In other geopolitical developments, U.S. Commerce Secretary Gina Raimondo told CNN that President Joe Biden's administration is "looking at" potentially lifting some tariffs on China to fight inflation.

"The president has asked us on his team to analyze that, and so we're in the process of doing that for him and he will have to make that decision," Raimondo said, adding that it "may make sense" to consider easing levies on certain products such as household goods and bicycles.

Currencies and oil

The U.S. dollar index, which tracks the greenback against a basket of its peers, was at 101.948 after seeing an earlier high of 102.211.

The Japanese yen traded at 130.71 per dollar, weaker as compared with levels below 128 seen against the greenback last week. The Australian dollar was at $0.7223 after declining from above $0.725 late last week.

Oil prices were higher in the afternoon of Asia trading hours, with international benchmark Brent crude futures up 0.68% to $120.53 per barrel. U.S. crude futures climbed 0.69% to $119.69 per barrel.

Clarification: This article was updated to more accurately reflect the moves in the U.S. dollar index during Asia trading hours on Monday.