|Some of the hacked sites showed a map of those killed in the Syrian crackdown [Al Jazeera]
Online activists have hacked into the official websites of seven major Syrian cities and several government departments, as security forces continue a crackdown on anti-government protests across the country.
The activist groups Anonymous and RevoluSec claimed responsibility on Monday for the operation, leaving their mark on sites such as the ministry of transport and ministry of culture.
Activists replaced the official sites with caricatures of Syrian President Bashar al-Assad and a message saying, "Don't let Bashar monitor you online", along with tips on how to avoid detection by Syria's online intelligence - known as the Syrian electronic army.
"First and foremost, this operation is about the people of Syria and our full support for them as they fight for freedom from oppression," a member of RevoluSec, who requested to remain unidentified, told Al Jazeera via a secure online discussion on Monday.
"We have common goals here in our actions: create a healthy dialogue and educate the public about the situation [and] expose the rampant censorship and human rights abuses.
"Essentially, we want to do everything in our power to help our brothers and sisters in Syria as they struggle for the basic human rights.
"You have throngs of people out in the streets of these various cities and they're all chanting 'Death and not humiliation'.
"Even children are chanting it. What does that tell you about the state of affairs in Syria? We want to help them where we can."
The websites for the cities of Homs, Aleppo, Latakia, Damascus, Tartous, Deir Ezzor and Palmyra were also hacked over the weekend, with the home pages replaced by an interactive map of Syria showing data on those killed in the government's crackdown after protests began in March, putting the death toll at 2,316.
Some of the websites have since been reset by their administrators, with each now only displaying a generic page.
The online operation comes amid a renewed government assault on the Syrian province on Homs, activists said on Monday.
Syrian tanks hit a strategic highway in the al-Rastan area of Homs in the early hours of Monday morning, apparently attempting to dislodge army defectors who had taken refuge there, activists and residents said.
Three inhabitants of the area were said to have been injured when troops loyal to Assad used heavy machine guns mounted on tanks to fire upon the town, after having surrounded it earlier in the night.
Activists reported hearing heavy explosions.
The army defectors have been supporting the pro-democracy protesters in al-Rastan, which is located about 20km north of the city of Homs, along the main highway leading to Turkey.
Activists also said that military reinforcements had been sent to Qusseir, a town on the border with Lebanon.
The Syrian army had been strengthening its presence in Qusseir on Saturday after civilians had attempted to flee violence in the country.
In-depth coverage of escalating violence across Syria
The initial deployments came a day after activists reported that security forces had killed 12 civilians in the town, and one more in Hama.
On Sunday, the UK-based Syrian Observatory for Human Rights reported the deaths of four more people, including that of Hassan Eid, the head of the surgery department at the state-run hospital in Homs.
Syrian state television said that Eid had been killed by "armed terrorist gangs".
The office of the United Nations High Commissioner for Human Rights in Geneva has put the number of people killed in the crackdown at more than 2,700 since March 15.
The Syrian authorities say 700 police and army personnel have been killed by "terrorists" and "mutineers".
Syria has been gripped by almost daily anti-government protests since March 15. While the demonstrations initially called for democratic reform, the protesters' stance has hardened in the face of a crackdown.
Damascus says that the protesters are not indicative of popular sentiment, and has blamed "armed gangs" and "terrorists" for the violence.