MADRID — Officials in Spain have increased security measures at consulates and public administrative buildings in the country after at least six letter bombs were mailed to several offices, including those of Prime Minister Pedro Sánchez and the American and Ukrainian Embassies.
An envelope sent by regular mail delivery to Mr. Sánchez’s office was intercepted by security services on Nov. 24 because it appeared to contain “pyrotechnic material,” the Spanish Interior Ministry said on Thursday.
That came after the national police said that they were investigating a letter bomb delivered to the Ukrainian Embassy that exploded on Wednesday, injuring the finger of an employee who had been inspecting it.
Since then, three more letter bombs containing similar material have been detected, Rafael Pérez, Spain’s secretary for state security, said at a news conference in Madrid on Thursday.
“The protection measures have worked, except in the case of the Ukrainian Embassy, and injuries have been avoided,” Mr. Pérez said during the conference.
Mr. Pérez did not point to a specific motive, but he said that the Spanish National Court on Thursday was investigating the incidents as possible acts of terrorism and called for “prudence.”
After the news conference, the Interior Ministry told The New York Times that another letter bomb had been sent to the U.S. Embassy in Madrid and that it had been safely detonated.
The increased security measures will vary but include more security patrols and agents, and specific alerts for couriers to more carefully filter mail, the Interior Ministry said in a separate statement.
The package that arrived in the Ukrainian Embassy on Wednesday had been addressed to Serhii Pohoreltsev, Ukraine’s ambassador to Spain, and Ukrainian officials said that it had exploded while the embassy’s manager was checking the mail. The manager was treated at a hospital for a minor injury to his right hand before being released.
Another letter bomb was sent to the headquarters of Instalaza, a Spanish firm that manufactures weapons and military equipment, including some used to help Ukrainian forces.
The Spanish police cleared Instalaza’s headquarters in the city of Zaragoza and sent bomb disposal teams to perform a controlled detonation of the letter bomb.
A fourth letter bomb, addressed to the director of the European Union Satellite Center, which provides security analysis for the bloc and is housed at an air base near a suburb to the northeast of Madrid, was detected early Thursday. Another letter, addressed to the Spanish defense minister, Margarita Robles, was intercepted Thursday morning at the Madrid headquarters of the Defense Ministry.
Initial indications suggested that the envelopes were sent from within Spanish territory, Mr. Pérez said, and the Spanish police were analyzing the packages for fingerprints and DNA, and carrying out handwriting tests.
With tensions high over Russia’s invasion of Ukraine, the Russian Embassy on Thursday condemned the letter bombs.
“Any threat of terrorist act, even more directed against a diplomatic mission, is totally condemnable,” the embassy posted on Twitter.
The Ukrainian Embassy did not immediately respond to a request for comment, but Ukraine’s foreign minister, Dmytro Kuleba, has ordered all of his country’s embassies abroad to bolster security.
José Bautista reported from Madrid, and Isabella Kwai from London.