isis militant waves flag
[Representational Image] A militant holds an Isis flag on a street in the city of Mosul on 23, June, 2014. Australian authorities have warned that Isis is seeking to build a 'distant caliphate' in Indonesia.Reuters

Raqqa-based Sunni militant outfit Islamic State has vowed to destroy Saudi Arabian prisons, where several jihadists are detained, said a report.

The latest Isis threat comes within a week of 47 people being executed by the Saudi regime on terrorism charges on Saturday. Of these, 43 were al-Qaeda militants.

The Islamist outfit has singled out the Tarfiya and al-Ha'ir prisons, which house al-Qaeda and Isis supporters, said a Reuters report. In July, a Daesh supporter had blew himself up in a car near al-Ha'ir prison.

"Islamic State always seeks to free prisoners, but we calculate that the ending of the issues of prisoners will not happen except with the eradication of the rule of tyrants, and then destroying their prisons and razing them to the ground," Isis stated in an online article on Tuesday.

Though ideological enemies, Isis and al-Qaeda are reportedly united against common enemy Saudi Arabia, which has declared them terrorist outfits.

Isis has claimed responsibility for attacks in the kingdom since November 2014, which have killed over 50, including Shi'ites and security personnel. They have also stepped up operations in neighbouring Yemen, as per the report.

However, Saudi officials have reportedly dismissed the ability of Daesh supporters to attack well-protected targets, as they act independently and depend on the group for limited logistical support.

In December, Yemen-based al-Qaeda in the Arabian Peninsula (AQAP) had warned against executing its members and threatened to kill Saudi security personnel.

Though the Saudi mass execution was supposedly a message to Sunni militants, the killing of some Shi'ite protesters — especially Shia cleric Nimr al-Nimr — has escalated tensions with Iran. They were reportedly linked to 2011 demonstrations inspired by the Arab Spring protests.

The tension between the Sunni and Shia powers increased after protesters stormed the Saudi embassy in Tehran and a consulate in Mashhad on Sunday. Later in the day, Riyadh said it was severing ties with Iran and asked Iranian diplomats in the country to leave within 48 hours.