The armed forces of Croatia are restricted by the Dayton Peace Accord. In 2002 the approximate number of active armed forces was 51,000 with 140,000 reserves. The army was estimated at 45,000. The air force had 3,000 members, and the navy had 3,000 sailors. Equipment included 280 main battle tanks and 24 combat aircraft. There are also 10,000 armed police. There were UN observers from 22 countries in Croatia, and the country provided support in peacekeeping missions in two foreign regions. Croatia's estimated military expenditure in 2002 was $520 million or 2.4% of GDP.