More regime attacks Saturday killed 60 people across the country, including 25 in Homs, just south of Houla, according to the Local Coordination Committees.
The Local Coordination Committees earlier Saturday decried the world's "apparent blindness" to the violence in Syria.
Months of U.N. Security Council attempts to resolve the crisis have failed to have any effect.
Ban said Friday the full cadre of 300 U.N. observers authorized by the Council will be in Syria in the coming days.
Ban issued a sobering report Friday on the Syrian crisis, detailing "continuing reports of a stepped-up security crackdown by the authorities that has led to massive violations of humans rights ... including arbitrary arrests, torture, enforced disappearance and summary execution of activists, opponents and defectors."
In a letter to the head of the U.N. Security Council, obtained by CNN, Ban said he is deeply concerned that the Syrian violence has not stopped despite the presence of the monitors and the agreement by both sides to a peace plan.
U.N. officials say more than 9,000 people, mostly civilians, have died and tens of thousands have been uprooted since the uprising began in March 2011. Opposition groups report a death toll of more than 11,000 people. Since al-Assad's government and opposition forces accepted Annan's peace plan in March, at least 1,635 people have been killed, the LCC said Saturday.
Following the reported massacre in Houla on Friday, the rebel Free Syrian Army implored members of the international "Friends of Syria" group to form a military coalition to launch airstrikes against al-Assad forces.
Meanwhile, the state-run Syrian Arab News Agency (SANA) said that "al-Qaeda-linked terrorist groups" massacred a couple and their six sons and a father and son in the rural village of al-Shumariyeh village in the Homs province.
The agency also said similar terrorist groups massacred a family of seven, including three children, in the same province's rural town of Taldo. The groups also burned houses and crops and blamed the army for bombarding the area, SANA reported. The terror group also sabotage the National Hospital in the area and attacked a law enforcement headquarters, SANA said.