A bomb slams into what activists say is the beleagured Syrian city of Homs.
It was one of three cities reportedly pounded by government air strikes on Saturday.
Other amatuer videos are said to show shelling in Syria's capital, Damascus, and Aleppo, the country's biggest city.
Reuters cannot independently verify the content of these videos, which came from a social media website.
Meanwhile, in Germany US Vice President Joe Biden met with the head of Syria's main opposition coalition, Mouaz Alkhatib.
The meeting comes as the US weighs whether to intervene in the Syrian conflict, which has claimed an estimated 60,000 lives.
Also on Saturday, Russian foreign minister Sergei Lavrov said he opposed using force to set up humanitarian safe zones inside Syria.
(SOUNDBITE) (English) RUSSIAN FOREIGN MINISTER, SERGEI LAVROV, SAYING:
"The situation on the ground requires not more military assets but immediate ceasefire and an immediate end to violence."
Moscow has been one the few backers of Syrian President Bashar al Assad during what has been a bloody 22-month uprising.
Air strikes continue to hammer Syria (1:31)
Feb. 3 - Bombs reportedly rain down on Damascus and Aleppo as world leaders search for ways to end the violence in Syria. Andrew Raven reports. ( Transcript )