Iran said its security forces on Saturday killed the mastermind of the attacks, and arrested seven people suspected of helping the militants.
Reportedly two guards, 10 government staffers and five civilians were killed in the attacks that simultaneously targeted the country's parliament and shrine of late founder of the Islamic Republic Ayatollah Ruhollah Khomeini.
On Friday, the ministry said 41 suspects had been arrested around the country in connection with the attacks.
On Friday, Iranian authorities said the assailants were Iranian nationals and that they had arrested six suspects, including one woman, since the attack Thursday in Tehran.
Iran had denounced US President Donald Trump's reaction to the attacks in Tehran as "repugnant" after he claimed that Iran was reaping what it sows.
The first attack was made by a four-jihadists team that carried assault rifles, the attackers wore suicide vests attempted to enter the administrative building of the Iranian Parliament.
Certainly, such attacks are practically impossible to carry out without support from Saudi Arabia and other regional parties like the Israeli regime, but the readiness on the Iranian side was considerable.
Authorities in Saudi Arabia are said to be now at alert after terror group, Islamic State popularly known as ISIS threatened to attack the kingdom.
Scanners, body checks and heavily armed soldiers or police have been rare sights in Tehran, which has seemingly been immune in recent years to the terror attacks plaguing much of the Middle East and Europe.
According to the ministry's statement, the five attackers were terrorists with criminal backgrounds who were linked to "Wahhabi and Takfiri groups".
The minister said the terrorist had fled the country after the attacks claimed by the Islamic State but did not reveal his identity or the country where he was killed.