A suicide truck bomb attack on a government checkpoint on the edge of the city of Hama in central Syria has left 30 dead, according to state media and activists.
State news agency Sana said Syrian rebels drove the truck laden with over a ton of explosives into the post at the eastern entrance of the city.
Sana said the explosion appeared to have set ablaze a fuel truck nearby, increasing the damage and casualties.
The British-based Syrian Observatory for Human Rights said the al Qaida-linked Jabhat al-Nusra, or al-Nusra Front, had carried out the attack.
The Geneva conference is an attempt to get sides to agree on a transitional government in Syria based on a plan adopted in that city in June 2012.
Syria's conflict, now into its third year, has left over 100,000 dead.