State media: Blast hits Syrian capital, civilians killed

• NEW: Arab League to increase the number of monitors in Syria to 150
• The blast occurs in a Damascus neighborhood, state TV reports
• Tens of people, including civilians, are killed and injured, state media reports
• Arab League monitors are in Syria on a fact-finding mission

(CNN) -- A "terrorist" explosion hit a neighborhood in the Syrian capital of Damascus, state media said Friday.

The blast killed and injured tens of people, including civilians, according to state TV, which said it is believed to be a result of a suicide bombing. It did not give an exact number.

Law enforcement personnel were also among those hit in the blast in Al Midan neighborhood, Syrian state news agency SANA reported.

The Local Coordination Committees of Syria, a network of opposition activists which collects reports from eyewitnesses and protesters, reported a heavy presence of ambulances and security forces in Damascus, with explosions heard around the area.

The apparent suicide attack comes as Arab League monitors are in the country to determine whether the Syrian government is abiding by an agreement to end its 10-month crackdown against protests.

The Arab League said Friday it was increasing the number of monitors in Syria over the next few days to 150 people, from about 100.

Between 5,000 and 6,000 deaths have occurred during the crackdown, according to various accounts.

President Bashar al-Assad's government says it is putting down armed terrorists, whom it blames for the bloodshed.

The blast comes two weeks after a pair of powerful car bomb explosions killed at least 44 people in Damascus.

The government blamed the strike on terrorists, while opposition forces accused the regime of carrying out the attack to back up its claim of fighting terrorists.

Car bombs and roadside bombs have been the weapons of choice for militants in other conflicts, such as Iraq and Afghanistan.

CNN cannot independently confirm events inside Syria because the government has restricted activities by international journalists.

CNN's Mohamed Fadel Fahmy, Nada Husseini and Pierre Meilhan contributed to this report.