Reports suggest explosive is similar to the five letter bombs sent to Ukrainian embassy and other targets in Spain

Spanish police reportedly cordoned off the area around the US embassy in Madrid and activated anti-terrorist protocols on Thursday after a letter bomb was allegedly delivered to the building, according to local media.

Spanish news outlet laSexta says that authorities have evacuated the nearby buildings and that police sources claim that Tedax bomb disposal units have already detonated the letter.

This comes after five letter bombs were sent to various targets across the country in the past two days, including to the Ukrainian embassy in Madrid, where one worker was injured on Wednesday after opening the package.

Explosive devices concealed in a postal package were also discovered at Spain's Defense Ministry, an air base and an arms factory. Spanish authorities say that a similar letter was sent to Spanish Prime Minister Pedro Sanchez on November 24 and was subsequently disposed-of by bomb-squad experts.

Spain's deputy interior minister Rafael Perez explained on Thursday at a press conference that the shipments were all sent in brown envelopes and contained pyrotechnic material and an activation system inside. He pointed out that according to preliminary analysis, the system within these packages is meant to cause a flare but not an explosion. He suggested that the letters do not justify raising the terror-threat level in the country and has encouraged people to stay calm.

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