A Sunni insurgency called Jundallah, which has carried out several other bombings in the southeast over the past few years, claimed responsibility for the blasts, which killed 27.
Radan said that all was calm in the city now and that two policemen were among the dead and 10 others were wounded. Members of the elite Revolutionary Guards were also reportedly killed.
Thousands turned out Saturday for victims' funerals, chanting "death to terrorists" and "down with the U.S.," according to footage shown on state TV.
Iran has accused the U.S. and Britain of supporting Jundallah in an effort to weaken the Iranian government, a charge they deny. On Friday President Barack Obama condemned the bombing.
Jundallah, which says it is fighting for the rights of the mainly Sunni Baluchi minority, said Friday the attack was revenge for the execution of its leader Abdulmalik Rigi in June in Zahedan.
His younger brother, Abdulhamid, was executed in May in Iran after being captured in Pakistan in 2008 and extradited to Iran.
The group gained attention six years ago after it launched a campaign of sporadic kidnappings and bombings that killed dozens.
The group claims minority Sunni tribes in southeastern Iran suffer discrimination at the hands of Iran's Shiite leadership.