Dow futures drop triple digits on weak China manufacturing data

U.S. stock-index futures declined early on Tuesday, as the U.S. dollar continued to slide and an indicator of China's manufacturing sector disappointed.

The China Caixin manufacturing PMI fell to 49.4 last month from March's 49.7, shrinking for a 14th consecutive month and coming in below a Reuters forecast for 49.9. Levels below 50 indicate contraction.

Meanwhile, the International Monetary Fund warned in a media briefing of a bumpy economic rebalancing in China and said the "larger spillovers" from its financial markets were a risk to economic growth in Asia.

The week is the last busy one for U.S. first-quarter earnings. On Tuesday, there were numbers from Pfizer, Estee Lauder,and Sprint.

The day will be light on U.S. data, with auto and truck sales for April the only report of note.

Loretta Mester, the president of the Federal Reserve Bank of Cleveland, will speak on a panel at the annual Financial Markets Conference in Florida on Tuesday. Dennis Lockhart, the Fed president of Atlanta, will give the welcoming address.

There will also be the latest data on weekly crude oil inventories from the American Petroleum Institute. This may pressure oil prices after reports of rising crude production among OPEC countries.

The slide in the U.S. dollar accelerated on Tuesday, falling below 106 against the Japanese yen. The dollar index against a basket of currencies is at its lowest since January 2015.