Tehraninfo-icon: Iraninfo-icon, one of the few countries not to have been affected by relentless terrorist attacks plaguing the Middle Eastinfo-icon, woke up to a new reality on Wednesday, when two of its iconic symbols, nations Parliament and the landmark mausoleum of spiritual leader and the founder of the Islamic Republic, Ayatollah Ruhollah Khomeini came under simultaneous terror attacks. 

At least twelve people were killed and 42 others wounded in the assaults, according to mediainfo-icon reports. In addition to the 12 victims, six assailants were killed: four at the Parliament, and two at the mausoleum

While Daesh immediately issued a claim of responsibility, suspicions in Tehran were also directed at Saudi Arabiainfo-icon, Iran's regional opponent, newly emboldened by a supportive visit from President Trumpinfo-icon last month, the New York Times reported.

Saudi Arabia recently raised the volume of criticism against Iran, and the country led a regional effort on Monday to isolate Qatarinfo-icon, the one Persian Gulfinfo-icon country that maintains relations with Tehran.

The attacks unfolded over several hours, starting around 10:30 a.m., when men armed with assault rifles and suicide vests -- some of them dressed as women -- descended on the Parliament building in downtown Tehran, killing at least one security guard, and wounding several others. The standoff lasted for about four hours.

Reports said, one attacker left the Parliament then ran around shooting on the street outside before he was shot dead. Another of his accomplices blew himself up on the fourth floor of the building.

Parliament was in session as the attacks unfolded, with live footage showing members continuing with routine businessinfo-icon even as gun battles were reported in surrounding office buildings.

Speaker Ali Larijani dismissed the attacks, saying they were a "trivial matter" and that security forces were dealing with them.

About the same time, around 10 miles to the south, two attackers entered the west wing of the sprawling Imam Khomeini shrine, a main destination for tourists and pilgrims. According to local news agenciesinfo-icon, at least one assailant detonated explosives in the western entrance. Another was reported to have committed suicide by swallowing a cyanide pill.

Mohammed Ali Ansari, the overseer of the mausoleum, said that militants who appeared to have explosives strapped to them "started shooting blindly and without a target upon entering the mausoleum."

Mizanonline news agency reported one assailant was arrested with six grenades. 

While terrorist attacks have become relatively commonplace in Europe and in most of the Middle East, Iran had remained comparatively safe. During May's election campaign, President Hassan Rouhani often pointed to that fact, lauding the country's security forces and intelligence agencies for their vigilance.

Iran a regional heavyweight has been helping both Iraqinfo-icon and Syriainfo-icon to battle the extremist groups, including Daesh, who have ravaged the two Arab nations. 

Daesh or ISIS is under increasing pressure in both countries, having lost significant territory in the face of offensives now targeting its last two major urban bastions, Raqa in Syria and Mosulinfo-icon in Iraq.

Iran's supreme leader Ayatollah Ali Khamenei said on Sunday that attacks by Deash in Europe and elsewhere showed that Western policies in the Middle East have backfired.

"This is a fire that (Western powers) themselves ignited and which now has backfired on them," he told a gathering of senior officials in Tehran.

WARNING In a statement, the Islamic Revolutionary Guard Corps partly faulted both Saudi Arabia and the United Statesinfo-icon government, saying: "Worldinfo-icon public opinion sees this terrorist attack -- which took place a week after the U.S. president held a meeting with the head of one of the region's reactionary governments -- as very significant," a clear reference to Saudi Arabia.

"The fact that Daesh has claimed responsibility for the attack is also deemed as showing that they were involved in this brutal act."

Brig. Gen. Hossein Salami, the deputy commander of the corps, vowed revenge, pledging, "We will avenge the blood of those martyred in today's terrorism attacks."