Arab separatists and the Islamic State (IS) issued competing claims for the attack, which prompted Iran to launch ballistic missiles at IS targets in Syria.
At least three people died and 24 others were injured in a suicide vehicle bomb attack on the police headquarters in Iran's southeast on Thursday, state media reported, adding that the perpetrator was killed.
"The suicide attacker set off the explosion after stopping at police headquarters in Chabahar".
The blast near Chabahar's police headquarters on Shahid Rigi Boulevard has been confirmed by Mohammad Hadi Marashi, the deputy security chief of the province.
Sistan-Baluchistan province, where the bombing hit, has always been a flashpoint, with a number of attacks reported in recent past.More news: Travis Scott slams rumors he cheated on Kylie Jenner
Images posted on Twitter purported to show thick smoke rising from the area. No militant group immediately claimed responsibility for the attack.
The TV station broke into its regular broadcast to report the attack, as such assaults are rare in the Islamic Republic.
Iran has stepped up security in border areas after gunmen in September opened fire on a military parade in Iran's southwestern city of Ahvaz, killing 25 people, nearly half of them members of Iran's elite Revolutionary Guards corps. "We express our condolences to the government and the people of Iran and the families of the victims of this attack", the Ministry of External Affairs said in a statement.
"India strongly condemns today's despicable terrorist attack in Chabahar, Iran".
Chabahar, near Iran's border with Pakistan on the Arabian Sea, is home to a new port recently built and is an economic free zone for the country.