An attack in Stockholm, Sweden today has led to a massive manhunt for a suspect who may be on foot.

Suspect has not been apprehended

According to a report by Fox News, a hijacked beer truck was driven directly into a department store, killing three and seriously injuring several others. The suspect is believed to have been wearing a gray hoodie at the time of the attack, though not much information is known about him otherwise. Sources confirm that at least two other individuals have been taken in for questioning in relation to the attack, but a spokesman for the Stockholm police force indicates the two may not actually be suspects.

Fox News reports that the police have had no form of contact with the truck driver since the incident. Police have also confirmed that subway traffic has been stopped as they search for the suspect. If he's apprehended quickly, more potential damage could be avoided.

Many say terrorism is to blame

The relative randomness of the events has led many to believe this was an act of terror. Sweden Prime Minister Stefan Lofven is one such person. In a statement made out of another part of the country today, the 60-year-old had no qualms about the nature of the bizarre incident. He said simply, "Sweden has been attacked. Everything points to the fact that this is a terrorist attack." The timing of this event also raises suspicions of terrorism.

Earlier this week, Russia, the country's Eastern neighbor and adversary, experienced their own terror attack, as a nail bomb, rigged to explode on a train, killed at least 11. Another random attack by ISIS in Iraq killed 22, and left dozens critically injured.

Countries worldwide are on high alert

Sources indicate the means of the Swedish attack may also point to terrorism.

Many terrorist cells have been known to use cars as implements in attacks, as their relative durability makes them more likely to do considerable damage. As Swedish officials, including King Carl XVI Gustaf, send their condolences, other countries are on high alert. Reports indicate that terror attacks in the last few months have seen a dramatic spike.

More unsettling still is a report that indicates "Sweden has produced more ISIS fighters per capita than almost any other European nation."

While ISIS is certainly not the only terror organization, recent reports indicating that up to four ISIS officials may been killed in recent weeks could mean these attacks are part of a retaliatory effort by the group. Those four allegedly deceased officials- Hazim al-Jabouri, Mohammed Bajari, Qidar Aqrawi, and Mujahid Anzi- all played very important roles in the governing structure of the organization. As attacks around the world seem to keep increasing, international security officials must work together to keep citizens safe.