In Iran where a Sunni rebel group has claimed responsibility for a suicide bombing that killed 42 people.
Victims from the blast include several senior commanders of the elite Revolutionary Guards Corps.
Iran blamed foreign elements behind the attack and vowed to strike back.
Revolutionary Guard commanders were on their way to a meeting with local tribal leaders in Sistan-Baluchestan. The planned meeting in the southeastern province aimed to step up unity between the Shiite and Sunni Muslim communities.
A suicide bomber laden with explosives around his waist blew himself up at the entrance of a sports complex where the meeting was to be held.
Deputy commander of the Guards' ground forces, General Noor Ali Shooshtari, and chief provincial commander, Rajab Ali Mohammadzadeh, were among those killed. Guard members and local tribal leaders were also killed in the attack.
Sunni rebel group, Jundallah, claimed responsibility for Sunday's bombing.
Iranian President Mahmoud Ahmadinejad accused unspecified foreigners of involvement. He expressed condolences to victims and ordered thorough investigation.
Iran's parliament speaker, Ali Larijani, also condemned the attack. He said it intended to disrupt security in southeastern Iran.