Story highlights Sixteen people were killed, more than 100 injured in two attacks

Protesters made a call for unity after the violence

(CNN) Half a million people took part in a colorful peace protest in Barcelona on Saturday after Spain's Catalonia region was hit with two terror attacks that killed 16 people.

The march was organized on social media with the hashtag #NoTincPor -- Catalan for "I am not afraid" -- a slogan shouted repeatedly by the protesters as they made their way down the Passeig de Gràcia shopping avenue.

Muslim women hold placards reading "Not in my name," "Terrorism doesn't have a religion" and "Islam is Peace."

Spanish King Felipe VI and Prime Minister Mariano Rajoy attended the protest, which was also a show of Barcelona's unity and cultural diversity. Protesters held signs saying "No to Islamophobia" as they marched alongside members of the city's Muslim community.

Some Muslim marchers held signs reading "I am Muslim. I am not a terrorist," and "Islam is peace."

"The solution is peace. Peace is equal for all," one protester told CNN Espanol.

Read More