What? More than 100 people died, most of them women and children, during a massacre in the Syrian city of Houla last week. Why? Why are they fighting? Syria is one of many countries in the Middle East where people, encouraged by popular uprisings, are hoping to bring change. The government of President Bashar al-Assad has used excessive force to crack down on the rebels. International attempts at a ceasefire have not been successful. How? How has the world reacted? US and world leaders used the recent massacre to step up pressure on Syria. Special UN envoy Kofi Annan says the country is at a tipping point. The US, Britain, France and Australia have all expelled Syrian diplomats in protest. Who? Who did it? At the moment, this is not clear. Each side blames the other. While government forces were shelling the area, a large number of those killed were shot in a house-to-house mass execution by men in uniform. The dead show signs of abuse, gunshots and knife attacks. The government says the killers were terrorists. The opposition says they were soldiers or a pro-government militia called Shabiha. Where? Where did it happen? The trouble started in Taldou, a village southeast of Houla. The rebel stronghold of Homs is just 20km to the south. When? When did it happen? Last Friday, around 1.30pm, villagers started to protest against the government. The army tried to disperse them with machine gun fire and five were killed. The rebels attacked the army, which responded with tank and mortar fire. The attack on civilians started just before sunset.