SHANGHAI—China’s central bank injected more cash into the financial system on Tuesday, stepping up its efforts to counter intensifying capital outflows from a weakening economy and tumbling stock market.

In its routine money market operation, the People’s Bank of China offered 150 billion yuan ($23.43 billion) worth of seven-day reverse repurchase agreements, a form of short-term loans to commercial lenders.

The central bank carries out such market operations every Tuesday and Thursday.

The PBOC injected a net 150 billion yuan into the financial system last week, marking its biggest pump priming exercise since the week of Feb. 7-13, when it injected a net 205 billion yuan.