Factory activity in the U.S. mid-Atlantic region unexpectedly contracted in February for the second month in a row, falling to the lowest level in eight months as new orders tumbled, a survey showed on Thursday.

The Philadelphia Federal Reserve Bank said its business activity index dropped to minus 12.5 from minus 5.8 in January, coming in far below economists' expectations for positive 1.0. It was the lowest level since June of last year.

A reading below zero indicates contraction in the region's manufacturing sector. The survey covers factories in eastern Pennsylvania, southern New Jersey and Delaware.

The gauge of new orders fell to minus 7.8 from minus 4.3.

The report is seen as one of the first monthly indicators of the health of U.S. manufacturing leading up to the national report by the Institute for Supply Management.