Violence escalates in Yemen as tribes clash with security forces

In the Yemeni capital Sanaa there’s been heavy fighting overnight and today, including loud explosions.  The BBC quoting local doctors and officials, says about 40 people are dead.  The violence comes after the breakdown of a truce between President Ali Abdullah Saleh and tribes loyal to Sheikh Sadiq al-Ahmar.  Amnesty International says security forces have killed dozens of people in the city of Taiz since Sunday, and scores of others have been arrested.  For more we’re joined by Susanne Dahlgren, Academy of Finland research fellow with the Helsinki Collegium for Advanced Studies.