The United States is closely following unrest in Kyrgyzstan, where riots have erupted in the capital Bishkek, a Pentagon spokesman said on Wednesday. Opposition protesters seized the parliament building in Bishkek as anti- government riots raged, leaving at least 19 dead and nearly 200 injured. 'The situation is a little unclear there as the US government continues to monitor the situation,' spokesman Bryan Whitman told reporters. The violence had not affected US forces stationed at the American embassy and at the Manas air base north of Bishkek, Whitman said. 'So far the situation there has not affected any of the US personnel assigned either at the embassy or at Manas,' he said. The US military relies on Manas as a vital hub to ferry troops and supplies for the NATO-led war in Afghanistan. About 38,000 troops came through the transit center between October and November of last year alone. Kyrgyzstan last year threatened to close the base after receiving a promise of more than two billion dollars in aid and loans from Moscow, which many saw as a sign of Russian resentment over the US military presence. Bishkek eventually agreed to keep the US base open after Washington more than tripled the rent paid to use Manas. 