At least three people were killed in stabbing attacks in Finland and Germany on Friday, a day after over a dozen people were massacred in terror attacks in two Spanish cities, media reports said.
Two people were killed and six were injured in a stabbing spree in the Finnish city of Turku on Friday, police said, after officers shot one suspect and warned several others could be at large.
"There are eight victims in the stabbing. Two dead and six injured," Turku police tweeted.
Police shot one suspect in the legs and arrested him. Security forces wrote on Twitter that police were "looking for other possible perpetrators".
In the western German city of Wuppertal, one man was killed and another injured in a stabbing incident.
The attacker was still on the loose, the police said.
"We can confirm there has been a deadly crime. One man has died and another man is in hospital," a German police spokeswoman told AFP.
The police said they were hunting for one or more assailants, but could not immediately provide more information about the circumstances of the attack.
The stabbing happened at around 1245 GMT in the city's Elberfeld area.
The death toll in a double attack in Spain rose to 14 on Friday, as the country reeled from the two vehicle rampages that saw drivers plough into pedestrians in Barcelona and Cambrils, another seaside town.
The emergency services said a woman injured in the Cambrils attack has died, bringing the total to 14 in both attacks.
Earlier in the day, the Spanish police said that they had shot dead 'four suspected terrorists' and left another injured, who later succumbed to his injuries early Friday in Cambrils.
The regional government of Catalonia, where both Barcelona and Cambrils are located, also confirmed the incident, which police had earlier qualified as a "possible terrorist attack."
Claiming the attack, jihadi-affiliated news agency Amaq said the attackers were "soldiers of Islamic State".
"We're united in grief," Spanish Prime Minister Mariano Rajoy said in a televised address after rushing to Barcelona, the biggest city in Catalonia, a region in Spain's northeast whose separatist government is defying Madrid.
"Above all, we're united in the firm intention to defeat those who want to take our values and way of life from us, "Rajoy added.
US President Donald Trump condemned the "terror attack" and said the United States will do whatever is necessary to help", adding: "Be tough & strong, we love you!"
French President Emmanuel Macron -- whose country has witnessed a series of bloody jihadist atrocities including a truck rampage in Nice in July 2016 that killed 86 people -- said his thoughts were with the victims of the "tragic attack".
The Nice carnage and other assaults including the 2015 shootings and bombings on Paris nightspots were claimed by the Islamic State, but it is believed to be the first Islamic States claim of an attack in Spain.
Catalonia has the highest concentration of radicalised Islamists in the country along with Madrid and the Spanish territories of Ceuta and Melilla in northern Morocco.