Nineteen people have reportedly been killed in shelling by tanks in residential areas in Syria as president Bashar al-Assad attempts to crush anti-government protests, defying calls for an end to the brutal crackdown.
Ammar Qurabi, head of the National Organisation for Human Rights in Syria, said 13 people were killed in the southern village of al-Harah on Wednesday.
Tanks also shelled a residential district in Syria's third largest city Homs and at least five people were killed, a rights campaigner in the city said. A sixth person was killed by a sniper shot to the head as he stood in front of his house.
Most were killed in shelling, but gunfire killed several of the victims, Qurabi said.
"Homs is shaking with the sound of explosions from tank shelling and heavy machine guns in the Bab Amr neighbourhood," Najati Tayara, a human rights campaigner, said.
The official Syrian news agency said one soldier was killed while in "pursuit of armed terrorist gangs".
Reports have also emerged that troops have deployed tanks around the central city of Hama, known for a bloody 1982 revolt which was crushed by government forces.
It is not possible to independently verify information on casualties as Syria bars international media from reporting inside the country.
Rights groups say about 800 people have been killed since protests began in March.
Reports of the latest bloodshed came as Ban Ki-moon, the UN secretary-general, urged Syria to halt mass arrests and to heed calls for reform.
Ban said UN humanitarian workers and human rights monitors must be allowed into Deraa, as well as other cities so as to assess the situation and needs of the civilian population.
"I urge president Assad to heed the call of the people for reform and freedom and desist from the mass arrest of peaceful demonstrators, and to co-operate with the human rights monitors," Ban told a news conference in Geneva.
"I am disappointed that the United Nations has not been granted access yet to Deraa and other places," he added.
Assad initially responded to the unrest, the most serious challenge to his 11-year grip on power, with promises of reform. He granted citizenship to stateless Kurds and last month lifted a 48-year state of emergency.
But he also deployed the army to crush dissent, in Deraa, where demonstrations first erupted, and then in other cities, making clear he would not risk losing the tight control his family has held over Syria for the past 41 years.
Activists said security forces used batons to disperse a pro-democracy demonstration by 2,000 students on Wednesday at a university campus in Syria's second largest city, Aleppo.
Amid the continuing turmoil, Catherine Ashton, the EU diplomacy chief, said on Wednesday that the bloc would look at fresh sanctions this week against Assad's regime after already honing in on his inner circle.
Asked by members of the European Parliament to explain why Assad's name was not on a list of 13 Syrian officials targeted by European Union sanctions, Ashton said "we started with 13 people who were directly involved" in cracking down on protests.
"We'll look at it again this week," she added.
"I assure you that my intention is to put the maximum political pressure that we can on Syria."
Speaking to the New York Times, a powerful cousin of the president said the Assad family was not going to capitulate.
"We will sit here. We call it a fight until the end... They should know when we suffer, we will not suffer alone," Rami Makhlouf, one of the 13 people targeted by additional sanctions, told the newspaper.
Makhlouf, a tycoon in his early 40s who owns several monopolies, and his brother, a secret police chief, have been under specific US sanctions since 2007 for corruption.
Demonstrators have shouted the name of Makhlouf as a symbol of graft in a country that has been facing severe water shortages and unemployment ranging from government estimates of 10 per cent to independent estimates of 25 per cent.
Makhlouf maintains he is a businessman whose companies provide jobs for thousands of Syrians.
Presidential adviser Bouthaina Shaaban told a New York Times correspondent, briefly allowed into the country, that the government was close to re-establishing order after unrest it blames on "armed terrorist groups".
"Now we've passed the most dangerous moment... I hope we are witnessing the end of the story," Shaaban said.
State-run TV said on Wednesday the government had formed a committee to come up with a new election law that would be "up to international standards".