FRANKFURT, Germany (AP) — Fears about international trade disputes and the conflict in Syria have sent the economic outlook lower among investment professionals in Germany.

The ZEW research institute index released Tuesday fell in April by 13.3 points to minus 8.2 points, the second sharp monthly drop in a row.

The index is now well below its long-term average of 23.5 points.

U.S. President Donald Trump has announced tariffs on steel and aluminum imports as well as on a range of Chinese goods, sparking concerns about retaliation and an escalating trade war. Germany's economy, the biggest in the 19-country euro currency union, is heavily dependent on exports such as industrial machinery and autos.

The ZEW is based on a survey of investment analysts about their outlook for the coming months.