BEIJING -- China experienced a sharp increase in property development investment and public works spending in the January-April period, according to statistics that the Chinese government released on Saturday.

The increased number of public works projects is an indication that China's economy is deepening its reliance on property investment and excessive debt. The rise in spending is getting a lift from municipalities, which have resumed raising funds through the so-called "shadow banking" sector.

The statistics also show that public sector investment and industrial production slowed during the first four months of the year.

Given this, China's economic outlook is becoming increasingly murky.

Investment in real estate development rose 7.2% on the year. The growth over the four months is attributed to a 55.9% rise in real estate sales from a year earlier.

Yet the strong gains were largely driven by property bubbles in Greater Beijing and Greater Shanghai. "Regional cities have more property inventories than at the end of last year," China's National Bureau of Statistics said in a note. "There is still considerable pressure to reduce those inventories."

Similarly, investment in fixed assets during the first four months of 2016 jumped 10.5% from a year earlier, while infrastructure investment soared 19%.

China's National Development and Reform Commission has unveiled plans to spend a total of 4.7 trillion yuan ($720 billion) on roads, railways, airports and other pieces of infrastructure through 2018.

But the spending spree will not necessarily have multiplier effects in manufacturing and other private sectors.

Indeed, private sector investment, which accounts for 60% of fixed-asset investment, rose only 5.2% during the January-April period, down from a 12.7% increase a year earlier.

"With demand remaining weak, companies are not eager to make investments," the National Bureau of Statistics said in its notes.

Industrial production increased 6% in April, down from a 6.8% rise a month earlier. The slowdown is being blamed on sluggishness in sectors with excess capacity.

Coal production fell 11% in April compared with a 4.5% drop in March, while steel output grew 0.5% in April, down from 3.3% a month earlier.

"China will now begin to reduce its steel and coal overcapacity," a reform commission spokesperson said. As such, the slump in China's industrial production will likely persist.