Hong Kong stocks closed lower Monday as investors remained cautious despite fresh state-backed measures to strengthen China's financial system.

The Hang Seng Index fell 237.75 points, or 0.9%, to close at 25,413.12, while the Hang Seng China Enterprises Index lost 125.30 points, or 1.5%, to finish at 8,429.73.

Eight major state-owned financial institutions, including Industrial and Commercial Bank of China (HKG:1398, SHA:601398), disclosed plans to raise or receive financial support to strengthen their core Tier 1 capital.

The measures signaled stronger government support for China's financial system amid ongoing economic headwinds, helping limit the broader market's decline.

Oil prices rose as tensions between the U.S. and Iran intensified, adding to concerns over inflation and the outlook for interest rates.

Investors are also awaiting U.S. inflation data later this week for further clues on the Federal Reserve's policy path, with markets pricing a 58% chance of a rate hike at the Fed's Sept. 16 meeting.

In company news, Medcaptain Medical Technology (HKG:2041) made its Hong Kong debut, closing 43% lower at HK$8.80, compared with its offer price of HK$15.42.