Syrian state television says twin explosions at security compounds in northern Syria Friday killed at least 28 people and wounded 235 others as a government crackdown on opposition protests spiked nationwide.

The blasts targeted a military intelligence building and a security force base in Syria's northern city of Aleppo, which had been relatively quiet since the uprising against President Bashar al-Assad's regime erupted in March.

Explosions Rock Northern Syrian City, 28 Dead, 235 Wounded

Television reports showed images of government buildings in central Aleppo with windows blown out and rubble strewn in the streets. It said that there were two blasts, one targeting a ?military security? branch and a second targeting the ?state security brigade? headquarters.

Explosions Rock Northern Syrian City, 28 Dead, 235 Wounded

The reports are blaming armed terrorists for the attacks, showing live footage of mangled, bloodied bodies on the pavement outside the shattered buildings.

Explosions Rock Northern Syrian City, 28 Dead, 235 Wounded

But rebel Colonel Riyadh al-Asaad, who heads the loosely-knit Free Syrian Army that is fighting government forces, denied responsibility for the blasts and accused the government.

The colonel said the Free Syrian Army had led an attack on the government buildings before the explosions, but had withdrawn by the time the bombs went off.

An opposition activist in Aleppo told Alhurra TV that he thinks the blasts were the work of Syria's secret police. He claims the police blamed the Free Syrian Army by calling a French television station to say the rebels were behind the bombings.

In an interview with VOA's Kurdish Service, human rights activist, Mahmoud Hamdush, said from near Aleppo that government forces are blocking roads in and out of the city center to prevent people from traveling to Aleppo's suburbs where large protests are being held against the government.

In Syria's third largest city, Homs, witnesses say heavy shelling targeted the Baba Amr district for a seventh day. Opposition videos showed the bodies of several children they say were killed by government shells.

One witness in the outskirts of Homs says security forces opened fire on worshippers leaving a mosque, and that several people are reported to be injured.

The activist told says that despite a relentless government assaults, rebels plans no surrender.

"I am, as an activist, being pursued after they issued a ruling to execute me immediately if I am arrested," said the man, who asked for anonymity and was interviewed via Skype. "Our colleagues are advising us not to turn ourselves in because the ruling stipulates that we will be executed."

Because of restrictions on reporting in Syria, VOA cannot confirm government or opposition reports.

The activist said supplies and food are running short in the Homs region.

"We are sharing whatever available from food and the humanitarian situation is so miserable that it can?t be described," he said. "While as youth we can manage, the kids and the elders cannot bear severe hunger. There [are] no medical supplies or milk for the kids and some bakers stopped making bread due to the shortage of wheat."

Another activist in Homs said that government attacks are not letting up and that even walking one block can be deadly.

"Every day is worse than the day before," he said of the assault, "more deaths, more injured, more destroyed buildings." He said hospitals are overflowing with the wounded.

Activists say hundreds of people have died since the offensive in Homs began early Saturday.

"Homs is becoming a ghost city," one of the activists told VOA on Friday. "No one is walking in the streets... Our situation is miserable."

Opposition activists in Damascus also report heavy government shelling in the outer suburbs and a fire at a hospital in Douma. Other reports tell of government attacks in several locations nationwide.

At a Damascus mosque, a cleric appointed with government backing claimed in a Friday prayer sermon that "outside forces" were responsible for sowing chaos and death in Syria.

Sheikh Ahmed Saleh said that money coming in from outside Syria is sowing chaos. He said government opponents do not want reform, but are trying to destroy Syria.

Syria analyst Nadim Shehadi of Chatham House in Britain says the Syrian government is stepping up its military onslaught to show that the protest movement is not peaceful.

"What the government is trying to do is convey the message that Syria is going into a civil war and that this is no longer a non-violent or peaceful protest against the government, and that this will certainly frighten any outsiders from intervening and will convey the image of another Iraq," he said.