Blast in Kabul ahead of assembly on future of U.S. troops --- (Reuters) - A suicide bomber rammed his car into an Afghan army vehicle providing security for a compound where Afghanistan's political and tribal elites are due to gather next week to debate a security pact with the United States. -- At least six people were killed and 22 wounded in the blast, said Sediq Sediqqi, an Interior Ministry spokesman. He said the casualties were a mix of soldiers and civilians. -- The blast occurred shortly after 3 p.m., fewer than 100 metres (yards) from a huge tent where more than 2,000 prominent Afghans are due to gather, a Reuters witness said. - More