The Mediterranean city has been in mourning after a driver ploughed into crowds on Las Ramblas on August 17, followed hours later by a vehicle attack in the seaside resort town of Cambrils.
A 51-year-old German woman died on Sunday 10 days after she was injured in a militant van attack in Barcelona, authorities said, bringing the total death toll from this month's twin assaults in Spain to 16.
Reports say no less than 500,000-strong demonstrators marched in Barcelona in a huge public rejection of violence following a recent deadly attack in the Spanish city, chanting: "I'm not afraid".
Claimed by the organization islamic State (IS), the terrorist attacks in Catalonia were perpetrated by six Moroccans between the ages of 17 to 24 years who grew up together in the small Catalan town of Ripoll.
Those who helped the victims, including the emergency services are said to have stretched back a mile, with Catalan flags and banners reading "we are not afraid".
The coordinated attacks on Las Ramblas, Barcelona, and Cambrils were Spain's deadliest Islamist terror attacks since the Madrid train bombings in 2004 committed by an al-Qaeda terror cell.
The phrase has grown from a spontaneous civic answer to violence into a slogan that Spain's entire political class has unanimously embraced. Four more are under investigation, two of them in jail.
In the northeastern town of Ripoll, home for numerous attackers, members of the local Muslim community and other residents gathered on Saturday in a central square to condemn the deadly attacks.
Sources from the independent bloc, which has an absolute majority in the Barcelona parliament, said the attacks won't change their October 1 goal. They and Abouyaaqoub were wearing fake suicide belts when they were killed, police said.