At least six people were killed on Tuesday in separate attacks in the restive southeastern region of Iran near Pakistan border, state media reported.

"Four people, including three military personnel, were killed in a terrorist attack in Bent," a small town in southern Sistan-Baluchistan, the official IRNA news agency said.

It also reported that two police officers were shot dead in their car in the town of Khash in the same province.

There has been no claim of responsibility for the attacks.

Sistan-Baluchistan, one of Iran's poorest regions, is mostly inhabited by the minority Baloch community, who largely practise Sunni Islam in a country where the theocratic government is staunchly Shiite.

The province bordering Pakistan and Afghanistan has long been plagued by unrest involving drug-smuggling gangs, rebels from the Baluchi minority and Sunni extremists.

On Monday, media reported the deaths of three police officers in two attacks, one of which was claimed by the Pakistan-based Sunni jihadist group Jaish al-Adl (Army of Justice in Arabic) that was formed in 2012.