Clashes between Syrian troops and army defectors are said to have killed 23 people Sunday, while activists reported attacks on workers striking against the government of President Bashar al-Assad.

The Local Coordination Committees, an opposition group, said government forces burned down a factory near the country’s largest city, Aleppo, because its workers were participating in the “strike for dignity” day.

A spokesman for the opposition in Homs said that most shops, markets and schools across the city were closed for the strike and that security forces had looted shut businesses.

The London-based Syrian Observatory for Human Rights reported fighting near the city of Idlib and in the rural areas around the capital, Damascus, with government forces pitted against army defectors and dissidents loosely grouped under the name Free Syrian Army. The fighting, which caused injuries but no confirmed deaths, is a sign that the nearly nine-month-old uprising is becoming increasingly violent.

“This has happened before,” said Rami Abdulrahman, director of the organization, citing incidents of armed dissidents battling security forces around the southern city of Daraa last month in which dozens were killed on both sides before more soldiers were brought in to subdue the situation.

The violence Sunday came as anti-government demonstrators in Amman, the capital of neighboring Jordan, stormed the Syrian Embassy. The Associated Press reported that two diplomats and four employees were injured in the attack, adding to regional anxiety that the unrest in Syria could destabilize neighboring countries.

Jordan has close economic and social ties with Syria, and many Jordanians worry that the increasing violence in Syria — which has a strong sectarian flavor — could spill over the porous borders.

On Friday, an explosion in southern Lebanon wounded five French peacekeeping troops. French Foreign Minister Alain Juppe said in a radio interview Sunday that he had strong reason to suspect that the attack originated in Syria.

Former Lebanese prime minister Saad Hariri tweeted that the explosion was a message from Assad.

“There is a lot of nervousness,” said Randa Habib, a political analyst based in Amman. “People are watching, scared of a spillover.”

Habib said that although the overwhelming political and popular consensus condemned the Assad regime, Jordan was reluctant to impose sanctions approved recently by the Arab League, because it would be economically disastrous for the already-struggling country; Syria is one of Jordan’s biggest trade partners. “It is too close for comfort,” she said.

Fordham is a special correspondent.