The Islamic State (IS) terror group has claimed responsibility for two suicide blasts which rocked a mosque during Eid al-Adha prayers in Yemen's capital Sanaa on Thursday killing 30 people."As part of a series of military operations in revenge for Muslims against the Shia Houthis, the suicide bombers blew explosive-laden belts amongst a gathering of the Shias in al-Blaili mosque," the IS said in a Twitter post.Witnesses said that the suicide bombings took place early morning in downtown Sanaa near police headquarters when worshippers were coming out of the mosque, Xinhua news agency reported.The toll may increase as many of the injured were in critical condition, medical officials said.