U.S. stocks closed mixed Thursday, as investors debated corporate earnings, renewed geopolitical tensions, and a recent spate of merger news. In U.S. economic news, initial claims for unemployment benefits rose in the past week. But a report on new orders for long-lasting goods in March came in better than expected. In international economic news, stocks came under pressure earlier in the day amid new worries about Ukraine, where government forces clashed with pro-Russian fighters in the southeastern city of Slavyansk. Russian President Vladimir Putin said any military action would "have consequences" for the government in Kiev. Russian forces are reportedly planning to conduct military drills in response to the action in Ukraine. European and Asian markets ended with mixed results.