The International Monetary Fund (IMF) said on Friday that it will revise up further China's economic growth forecast for 2017 due to a strong start of the year.

China's "growth in the first quarter has surprised almost across the whole range of indicators," Markus Rodlauer, deputy director of the IMF's Asia Pacific Department, told Xinhua at a press briefing.

The overall economy posted a forecast-beating growth rate of 6.9 percent in the first quarter of 2017, compared with a year earlier, he noted.

The upbeat reading, the quickest increase in 18 months, was above the full-year growth target of around 6.5 percent in 2017 and the 6.8-percent increase registered in the fourth quarter of 2016, according to China's National Bureau of Statistics.

Rodlauer attributed China's strong growth in the first quarter of the year to several factors, including the fiscal policy support, high credit expansion, strong real estate sector and improved external environment.

In its latest World Economic Outlook released Tuesday, the IMF had upgraded its forecast for China's economic growth in 2017 to 6.6 percent, 0.1 percentage point higher than its forecast in January, citing stronger-than-expected momentum for the world's second-largest economy.

"We have to look again at that forecast in this upside risk, and we will revise it up further before even though we do see also some likelihood that some of these strong momentum will slow in the second half (of the year)," he said.

Rodlauer noted that Chinese authorities are taking important measures to restrain the rapid growth of the real estate sector in some areas and rein in financial stability risks in the shadow banking system.

"As these measures take hold, we do expect some slowdown of the very strong momentum going into the second half," he said.

Christine Lagarde, managing director of the IMF, said Thursday there were good economic data coming from China and the Chinese economy is continuing rebalancing from investment towards consumption and services, but the country needs to rein in credit growth to secure sustainable economic growth.

The IMF is expected to update its forecasts for global economy in July.