Fifteen members of Iran's elite Revolutionary Guards were among those killed in the attack, which struck ahead of a meeting between Revolutionary Guards commanders and tribal chiefs.
Throngs of uniformed mourners paid their respects for the dead at a funeral on Tuesday in Tehran, Iran's capital.
A Sunni group, Jundollah, has claimed responsibility for the attack, but Iranian authorities have accused Pakistan of having links to the bombers, a charge Pakistan denies.
Manouchehr Mottaki, Iran's foreign minister, said members of the group accused of mounting the attack regularly criss-cross the frontier with Pakistan.
"Members of this terrorist group regularly violate the border and launch attacks inside Iran," he said, without naming the group.
"They cross into Iran illegally. They are based in Pakistan."
Also on Tuesday, a senior commander called for permission to go into Pakistan to hunt for who he called "terrorists", state television reported.
Brigadier-General Mohammad Pakpour, the head of the Revolutionary Guards ground forces, said his forces are ready to confront those believed responsible for the attacks.
"So far Pakistan has not co-operated with us and today the main counter-revolutionary sanctuary is Pakistan," the AFP news agency quoted Pakpour as saying.
"The terrorists are being trained in that country and Pakistani officials should have the ability to confront the elements on their own soil."
Earlier, Major-General Muhammad Ali Jafari, the head of the Revolutionary Guards, named the prime suspect behind the bombing as Abd ul-Malik Rigi - who is believed to be based in Pakistan.
Jafari said Tehran would send a delegation to Islamabad to deliver "proof to them so they know that the Islamic Republic is aware of Pakistan's support".
He also expressed his belief that US and British intelligence services were involved and that there would "have to be retaliatory measures to punish them".
But a Pakistani foreign ministry spokesman has rejected the claim.
"Pakistan is not involved in terrorist activities ... we are striving to eradicate this menace," he said.
Washington has also denied involvement with the group, which it has labelled as a "terrorist" organisation, and has condemned the attack.