According to an initial assessment, traces of the powerful explosive TATP were found at the ruins of the suspected bomb factory used by the Barcelona attack cell.

TATP is made by adding an acid to a mixture of acetone and hydrogen peroxide solution and can easily result in accidental detonation if mistakes are made in preparation.

The Spanish newspaper El Pais was first to report traces of TATP were found in the ruins of the suspected bomb factory in Alcanar, about 125 miles drive south along the coast from Barcelona.

The blast Wednesday evening at a house in Alcanar came before the Barcelona attack, in which 13 people were killed and 120 were wounded.

The home was almost destroyed by an unexpected explosion.

One person, a Spanish national, died in the blast, and another was seriously injured -- and later arrested.

Source: MENA