In his message of condolences, Butkevičius said the Monday explosions were an attack against humanity.
"On behalf of the government, I extend my deep condolences to the families of those killed and wish fortitude and strength to all the injured. In the face of threats to democracy and common security, we sympathize with all US citizens and we are convinced that the evildoers will soon be identified and brought to justice. We are standing together with you in the fight against the evil and we have no doubt that we will prevail," Butkevičius said.
"We are shocked by the explosions during the Boston Marathon, which left people dead and many people injured. I strongly condemn the culprits of this attack and extend my sincere condolences to the families, relatives and friends of those killed," Linkevičius wrote in his letter.
On Monday, two explosions near the finishing line of the Boston Marathon left three people dead and at least 140 injured.
There is no information about Lithuanian citizens injured or killed during the Boston explosions, Lithuania's Ministry of Foreign Affairs says.
Lithuanian Ambassador to the United States Žygimantas Pavilionis told news website delfi.lt that six Lithuanians took part in the marathon and they contacted the embassy to say they were safe and sound.
