Beirut ? Syrian authorities have charged a U.S.-born Syrian blogger with trying to incite sectarian strife, activists said Tuesday, while regime forces fired on a funeral procession in a restive northwestern region, capping a bloody day of attacks that left at least 28 people dead.

Razan Ghazzawi is the latest among dozens of activists, journalists and bloggers who have been detained since the revolt against President Bashar Assad began nine months ago, triggering a brutal crackdown that the U.N. estimates has now killed more than 5,000 people and put thousands into security lockups.

Ghazzawi, 31, had been documenting human rights abuses in recent months, and was arrested Dec. 4 at the border while on her way to Jordan for a conference on press freedoms.

On Monday, she was charged by Syrian authorities with trying to incite sectarian strife, spreading false information and weakening national sentiment — a charge often leveled against those who challenge the Syrian regime, according to rights activists. The charges could carry a prison sentence of up to 15 years.

The Syrian Center for Media and Freedom of Expression in the Arab World where Ghazzawi worked said in a statement Tuesday that Ghazzawi denied all the charges.

“We demand the immediate and unconditional release of our colleague Razan Ghazzawi as well as an end to her trial and the annulment of the completely baseless charges against her,” the SCM said.

Despite growing international pressure on his regime, Assad has forged ahead with his crackdown, unleashing security forces and the army on cities in a bid to crush an uprising inspired by similar revolts across the Arab world.

On Tuesday, regime forces fired on thousands of people taking part in a funeral procession in the northern city of Idlib, killing two people and pushing the day’s death toll to at least 28.

The flare-up of violence near the Turkish border is fresh evidence that the Syrian uprising is growing into a full fledged insurgency.

Military defectors known as the Free Syrian Army have recently been fighting back with increasingly sophisticated attacks, giving many protesters hope of a fighting chance against Assad’s fiercely loyal forces, but also complicating an uprising that was once largely peaceful.

The defectors have found shelter in cities and villages among sympathetic Syrians, their presence giving the regime a pretext to crack down even more strongly than before. Authorities have also used the attacks by defectors to support their official narrative that the unrest in Syria is the work of armed gangs and terrorists, not true reform seekers.

The U.S., EU and the Arab League have imposed economic sanctions on Syria, and Washington and its Western allies are pushing for U.N. sanctions as well on Assad’s regime.

Russia and China — two veto-wielding countries on the U.N. Security Council — have resisted the idea, and on Tuesday Russia’s foreign minister accused the West of taking an “immoral” stance on Syria and ignoring violence by the Syrian opposition.

Sergey Lavrov added that armed groups attacking Syrian government forces are “aiming to provoke a humanitarian catastrophe and get a pretext for demanding an outside interference into the conflict.”

Tuesday’s violence began in two villages near the Turkish border, after security forces entered and shot dead two civilians, according to Rami Abdul-Rahman of the British-based Syrian Observatory for Human Rights.

Regime forces also swept through villages in the area and attacked infiltrators at the border.

Residents of the villages of Maaret Musreen and Kfar Bahmoul responded by closing a main road with rocks and burning tires to the Syrian troops, who then opened fire at random, Abdul-Rahman said, killing 11 civilians and wounding 26.

“These are intentional killings by the terrorists gangs of the regime,” said Abu Mohammed, a resident of the nearby town of Maaret al-Numan, said,

“We will not abandon our demands,” he said. “We want the downfall of the regime and we want the president to be put on trial, because he is behind the killings that the Syrian people are being subjected to.”

Army defectors later retaliated by attacking a security convoy in the nearby town of Bab el-Hawa with AK-47s and rocket propelled grenades, killing seven troops, activists said.

Abdul-Rahman said security forces also killed three other people in the provincial capital of Idlib and two in the central province of Homs. The Local Coordination Committees, another activist group, gave a similar death toll.

Syria’s state media reported that border guards intercepted 15 gunmen trying to sneak into the country from Turkey on Monday night. It said two were killed in the ensuing firefight and others were wounded.

It was the second such infiltration attempt from Turkey in a week.

Members of the Free Syrian Army have found shelter alongside thousands of Syrian refugees on the Turkish side of the frontier, making use of mountainous terrain, local smuggling networks and support among villagers on the Syrian side to stage cross-border attacks.

SANA also reported that “armed terrorists” — its usual term for regime opponents — shot and killed Brig. Gen. Ghanem Ibrahim al-Hassan, who teaches at the Assad Military Engineering Academy in the town of Saraqeb in Idlib.

Since the revolt began, the Assad regime has blamed the bloodshed on terrorists acting out a foreign conspiracy to divide and undermine Syria. Until recently, most deaths appeared to be caused by security forces firing on mainly peaceful protests.