An employee of Ukraine's embassy in Madrid has been "lightly" injured after a letter bomb blew up as he handled it, a police source said.

"National Police were informed around 1:00 pm (12:00 GMT) of an explosion at the Ukrainian embassy in Madrid. It happened when one of the embassy employees was handling a letter," the source said on Wednesday.

"This employee was injured, apparently lightly, and he went himself to a hospital," the source added.

Police have opened an investigation "which includes the participation of forensic police," the source said without giving further details.

Strengthening security at embassies

A security cordon has been put in place by the police around the embassy, located in a residential area in northern Madrid. 

Ukraine said it will strengthen security at all the country's embassies after the incident.

"Foreign Minister Dmytro Kuleba instructed to strengthen the security of all Ukrainian embassies," Ukraine's foreign ministry spokesperson Oleg Nikolenko said on social media in English. 

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