An audio recording featuring a leader of the al-Qaida-linked Islamic State of Iraq (ISI) threatened NATO-member countries and warned Monday that the recent suicide and car bombing in Sweden were "only the beginning of a new era in our jihad."

In the two-minute recording, ISI "War Minister" Abu Suleiman al-Nasser told NATO countries to "withdraw their troops from Afghanistan immediately and unconditionally," and ordered them to "stop their war against Islam."

Should the countries not follow these demands, warned Nasser, "You'll have no security" and "should expect that we will strike at the heart of Europe."

The ISI praised Saturday's car bombing and suicide attack, publishing a picture of the suspected bomber Taimour Abdulwahab al-Abdaly.

The ISI's threat should be taken seriously considering its recent history of terrorist attacks.

In October, the ISI claimed responsibility for an attack on a Baghdad church in which it held hostages in a stand-off, demanding the release of al-Qaida members.  When Iraqi security forces stormed the church to try to free the hostages, more than 50 people were killed in the ensuing gunfire.  The group also claimed responsibility for other bombings in Baghdad earlier this year in January and April and was suspected to be behind several bombings in August.

The ISI is not the first al-Qaida-linked group this year to promise ensuing terror following an attack. The Somali militant organization al-Shabaab announced it would "unleash a new tide of terror" in July after its bombing of several targets in Kampala, Uganda, which killed more than 70 people.