Iranian state media said that up to 20 members of the Islamic Revolutionary Guard Corps were killed when a terrorists carried out a suicide bombing of bus in southeast Iran. Video showed a bus mangled alongside a road at night. There were up to “thirty martyrs,” Fars News said as the casualties appeared to increase throughout the evening.The attack comes as the US and other countries are attending meetings in Warsaw that are widely seen as part of an attempt to confront Iran in the region.According to Iranian media a suicide bomber struck a bus that was travelling on a road not far from the Pakistan border between Zahedan to Khash. A statement from the IRGC’s communication’s department of the Quds Force said that the suicide attack was carried out by “Takfiri terrorists,” a term usually indicating Sunni jihadist groups. It said a unit of IRGC troops were returning from completing a border mission and were on their way home. The bomb was detonated adjacent to the bus, which was carrying the IRGC unit. The statement did not provide casualty details.The southeastern area of Iran has suffered a wave of attacks by various armed groups, such as Jaish Al-Adl, a group based in Sistan and Baluchestan province. In September gunmen attacked a military parade in Ahwaz, an area in southwestern Iran. Other attacks by Kurdish groups in northeastern Iran have also targeted the IRGC.An IRIB correspondent said the Jaish al-Adl had claimed responsibility for the attack, but no public statement from the group was available for media.