SAN'A, Yemen — Yemen released 170 men it had arrested on suspicion of having ties to Al Qaeda, security officials said Sunday, two weeks after the terror group announced that Yemen had become the base of its activities for the whole Arabian peninsula. In the past, such releases have raised concern in the United States and increased its reluctance to release Yemeni detainees from the Guantanamo Bay detention facility. Yemen has said it expects most of the 100 remaining Yemenis at Guantanamo to be sent home after President Barack Obama ordered the prison shut within a year.