The border guards were "abducted between 4 am and 5 am in the Lulakdan area of the border by a terrorist group," the official IRNA news agency said.

Lulakdan is a small village 150 kilometres (about 90 miles) southeast of Zahedan, capital of the southeastern province of Sistan-Baluchistan.

The 14 were involved in "a security operation" and included two members of the elite Revolutionary Guards intelligence unit, seven Basij militiamen and five regular border guards, the Young Journalists' Club (YJC), a state-owned news website, said.

The report was deleted from the YJC website shortly afterwards.

The province has long been a flashpoint, with Baluchi separatists and jihadists based in Pakistan regularly attacking Iranian security posts.

On September 28, the Guards said they had killed four militants who had slipped across the border.

Sistan-Baluchistan has a large, mainly Sunni Muslim ethnic Baluchi community which straddles the border.

Sunni extremist group Jundallah (Soldiers of God) launched a bloody insurgency in the province in 2000 targeting the security forces and officials of Iran's Shiite-dominated government.

The campaign peaked with a spate of deadly attacks from 2007 -- including twin suicide bombings against a Shiite mosque that killed 28 people -- but abated after the group's leader was killed in mid-2010.

In 2012, Jundullah members formed a successor organisation called Jaish al-Adl (Army of Justice), which has carried out a spate of attacks on the security forces.

Iran has alleged that the group has received support from the US, Israel and Saudi Arabia, with the complicity of Pakistan.