Prosecutor Alex Perrin said the killings were "totally premeditated" by the 45-year-old, who was not known to the police or intelligence services.
The incident on August 4, which saw 2,750 tonnes of improperly stored ammonium nitrate explode, killed more than 200 people.
There are fears of a renewed US-Iran clash a year after the US drone killing of the Revolutionary Guard chief, in the dying days of Donald Trump's presidency.
The gesture forms the foundation of modern relations between Germany and Poland.
Sixteen people died in the attacks on Las Ramblas and in the coastal town of Cambrils.
Thousands sang and chanted as they marked the first anniversary of major clashes in Hong Kong between police and pro-democracy demonstrators.
A few hundred demonstrators held flash-mob protests during lunchtime at multiple malls in Hong Kong on Tuesday.
Turkey is celebrating the 96th anniversary of the Republic. Marking the day, President Recep Tayyip Erdogan visited Anitkabir, the mausoleum of Turkish Republic founder Mustafa Kemal Ataturk, in the capital, Ankara.
Pro-democracy protests are expected to take place in Hong Kong on Tuesday - on the 70th anniversary of the founding of the Chinese Federal Republic. It's in defiance of a ban on the demonstrations taking place having been confirmed by the authorities.
A special anniversary edition of the album has been released with new mixes and unreleased session recordings and demos
The third joint rehearsal for the upcoming National Day celebrations concluded early Monday morning in Beijing, eight days ahead of the 70th anniversary of the founding of the People's Republic of China (PRC), which falls on Oct. 1
The 'Bat-Signal' beamed out across the globe at 8 p.m. local time on Saturday evening (September 21) to mark Batman turning 80