Aftermath of the suicide attack on a bus in Volgograd. Image from RIA Novosti.

The southern Russian city of Volgograd has suffered its second suicide attack targeting public transportation in two days. Yesterday’s blast took place at the city’s train station, and today, a suicide bomber destroyed a trolley in the city. Both attacks are likely to have been carried out by the Islamic Caucasus Emirate, an al Qaeda-allied group whose leader has ordered his fighters to attack the 2014 Winter Olympics in nearby Sochi.

Today’s suicide attack was designed to maximize casualties; the blast took place on a trolley at around 8 a.m. local time, as residents were commuting to work. The suicide bomber, who is believed to be a male, detonated the “equivalent to at least 4 kg TNT” on the crowded trolley, ITAR-TASS reported.

The blast demolished the trolley, peeling off the roof and sides. Reports indicate that at least 15 people were killed and 27 more were wounded; some of the wounded are in critical condition.

Today’s terrorist attack took place just one day after a female suicide bomber, or Black Widow, killed 17 people and wounded dozens more in a suicide attack at the main train station in Volgograd. Yesterday’s attack is thought to have been carried out by a woman who had been married to known jihadists from the Islamic Caucasus Emirate.

While no group has claimed credit for the last two attacks, they were most certainly carried out by the Islamic Caucasus Emirate, which seeks to establish an Islamic state in southern Russia. The Islamic Caucasus Emirate claims that Volgograd “is located in the northern part of the Islamic state of the Caucasus Emirate,” according to Kavkaz Center, which distributes propaganda for the terror group.

The Islamic Caucasus Emirate is the only group operating in southern Russia known to use suicide bombers, and its Riyad-us-Saliheen Brigade has trained females for suicide missions. The terror group has announced that it seeks to disrupt the 2014 Winter Olympics slated for February in Sochi.

In July this year, Islamic Caucasus Emirate leader Doku Umarov issued a statement calling for further attacks aimed at disrupting Russia’s plans for the Winter Olympics in Sochi, according to Kavkaz Center. He stated: “We know that on the bones of our ancestors, on the bones of many, many Muslims who died and are buried on our territory along the Black Sea, today they plan to stage the Olympic Games. We, as the Mujahedeen, must not allow this to happen by any means possible.”

In that statement, Umarov also declared that the Islamic Caucasus Emirate is allied with al Qaeda and other international terrorist groups.

“We are a part of the global jihad,” he said.

The Islamic Caucasus Emirate appears to be targeting public transportation in Volgograd in order to sow panic and deter visitors from traveling to the region for the Olympics. On Oct. 21, another Black Widow detonated explosives on a bus at a train station in Volgograd. That attack was carried out by a Dagestani woman named Naida Asiyalova. She was married to a jihadist who was wanted for executing bombings in the Caucasus. [See LWJ report, Suspected ‘Black Widow’ suicide bomber kills 6 in southern Russia.]

The blast on the bus today sparked panic in Volgograd and as far away as Moscow as rumors of other bombings circulated. In Volgograd, some commuters left buses and trains after rumors of other attacks in the city were reported on social media sites, according to RIA Novosti.

For more information on the Islamic Caucasus Emirate’s use of female suicide bombers in its operations in Russia, see LWJ report, ‘Black Widow’ suicide bomber strikes at Russian train station.