Spain's Ibex-35 index plummeted 1.41 percent on Friday morning after Barcelona's and Cambrils' terrorist attack on Thursday.

Companies belonging to the tourist sector led falls with Airline group IAG falling 2.17 percent and Spain's airport operator AENA losing 1.55 percent respectively.

Only engineering and infrastructure company Tecnicas Reunidas gained, rising 0.90 percent.

Barcelona is a major tourist destination with over 32 million people calculated to have visited the city in 2016, while Cambrils is also a tourist destination located in the coast of the Tarragona province.

However, Thursday's violence attacks on Barcelona and Cambrils might pose threat to the flourishing tourist industries there, as people would consider to avoid the areas out of safety and security concern.

On Thursday afternoon, a van mowed down people from the top of Las Ramblas, the famous street in the center of Barcelona, going across around 500 meters, killing 13 people and injuring more than 100 others.

In Cambrils, hours after the attack in Las Ramblas, Catalan police took down five terrorists. Six people were injured including three policemen during the shootout.

It was the worst attack in Spain since March 2004, when Islamist militants placed bombs on commuter trains in Madrid, killing 191 people and wounding more than 1,800 others.