The volume of weapons exported to the Middle East has risen sharply in the last four years, threatening to destabilize the volatile region further, a leading Swedish think tank warned Monday. The Stockholm International Peace Research Institute said arms exports to the Middle East increased 38 percent in the period 2004 to 2008, compared with 1999 to 2003. The United States supplied most of the arms although major shipments also came from France. The United Arab Emirates was the biggest importer of weapons in the region - and the third biggest in the world, after China and India, SIPRI said in a report on global arms transfers. In the 2004-2008 period, the UAE bought 80 F-16E combat aircraft from the US and 50 Mirage 2000-9 fighters from France, it said. "This is of course a big concern in a region where we see a lot of tension and full-out conflicts," SIPRI researcher Pieter Wezeman told The Associated Press. He warned that growing arsenals in the Gulf could trigger a response from Iran and encourage it to pursue nuclear weapons.