Iran vows to take 'vigorous revenge' over killing of Qassem Soleimani

*Tehran:* Iran on Friday vowed to take a "vigorous revenge" over the killing of General Qassem Soleimani, the head of Iran's elite Ayatollah Ali Khamenei (IRGC). Iranian Leader Ayatollah Ali Khamenei paid a tribute to Soleimani as a "martyr" and announced three-day national mourning in the country, reported Al Jazeera. Iran...