Polish President Lech Kaczynski on Monday sent a message of condolence to his Russian counterpart Vladimir Putin over a bomb explosion in a Moscow market.
In the message, Kaczynski said the news about the tragedy had plunged him into anguish and regret, the PAP news agency reported.
"On behalf of the Polish nation, I would like to convey to you our condolences and deep sympathy to the families of the victims, " said the president.
"I wish quick recovery to the injured, and together with the Russian nation I join in the thoughts and prayers for all the afflicted," he added.
At least eight people, including three children, were killed when a homemade bomb ripped through the Eurasian section of Cherkizovsky market in Sirenevy Bulvar district, northeast Moscow, at 10:40 a.m. local time (0640 GMT).
Two men were suspected of staging the explosion, which also wounded 41 others.
Moscow's chief prosecutor Yuri Syomin said the explosion was most likely a criminal act, but the possibility of a terrorist attack had not been ruled out.