Security forces in Syria shot dead at least 12 people in operations across the country on Friday, the Syrian Observatory for Human Rights said, as pressure mounted on the regime to end the crackdown.
The latest deaths came after UN chief Ban Ki-moon called for "coherent" global action over President Bashar al-Assad's deadly response to dissent, as dissidents marked six months of anti-regime protests in Syria.
And Turkish Prime Minister Recep Tayyip Erdogan, in the Libyan capital on the final leg of his "Arab Spring" tour, lashed out at Assad, telling him that the era of oppressive dictators is past.
"Four people were killed and 11 more were wounded -- three of them seriously -- during search and seize operations in the town of Hilfaya" 17 kilometres (10 miles) from Hama city, the Britain-based group told AFP in Nicosia.
"One person was also killed in the village of Khattab in Hama province," it added.
Elsewhere, three people were killed in the villages of Sarjeh and Kfar Weid in the northwestern region of Jebel al-Zawiya after being detained, the Observatory said.
In the central city of Homs, two demonstrators were shot dead by security forces when several thousand people gathered to protest, activists said.
One person was shot dead by security forces in the Nahr Aisha quarter of Damascus, and one was killed in Douma, also in the capital, the Observatory said.
It also reported the discovery of eight bodies -- six in Jebel al-Zawiya and another two in Homs. It said most had been killed over the past 24 hours.
State television said one member of the security forces was killed and another four were wounded at Basr al-Harir in Daraa province in the south during an attack by "armed groups."
In the city of Hama itself, security agents "surrounded the Saad bin Abi Waqas mosque" anticipating an anti-regime protest after Friday prayers, activists there reported.
In July, Hama saw protests by hundreds of thousands of people calling for the downfall of Assad's regime, but the rallies were put down by security forces using deadly violence.
Citing activists on the ground, the Observatory also reported several tanks and troop transports bearing down on the northwest town of Maaret al-Numan in Idlib province.
It said security operations in Idlib on Thursday resulted in the deaths of two people, 73 arrests and another nine people missing.
Elsewhere, communications were still cut on Friday in Zabadani some 50 kilometres (30 miles) northwest of Damascus. One man has been reported killed and 153 people arrested there since Tuesday.
Opposition protesters had called for more rallies on Friday, the Muslim day of weekly prayer when demonstrations tend to be the heaviest, undaunted by the crackdown that the United Nations says has killed more than 2,600 people.
The rallies were to be staged under the slogan "we advance toward the fall of the regime."
Ban said on Thursday of Assad that "when he has not been keeping his promises, enough is enough and the international community should really take coherent measures and speak in one voice."
The UN chief has had several telephone conversations with Assad since the protests erupted on March 15, during which the president repeatedly promised to end the bloody crackdown and institute political reforms.
"Six months. More than ever determined to (continue) the March 15 uprising," activists wrote on Facebook page The Syrian Revolution 2011, one of the main engines of the revolt.
"We have been massacred and we are more determined than ever; we have been thrown in prison and are more determined than ever," the page said. "The revolution has burst forth and will not stop until the regime is overthrown."
In Tripoli, Erdogan said on Friday that "those who oppress the people of Syria... should understand that his time is past because the era of repressive regimes has ended."
A Turkish daily, meanwhile, quoted the Turkish premier as saying Ankara has warned Iran "not to spoil" the Syrian leadership by encouraging Damascus in its crackdown on dissent.
Erdogan said he had discussed the matter with President Mahmoud Ahmadinejad of Iran, which accuses its arch-foes Israel and the United States of stirring up trouble in Syria.
Syrian opposition figures in Turkey announced a list of names of people on the "Syrian National Council" on Thursday, in a move welcomed by the US State Department.
The Red Cross meanwhile condemned attacks on medical services in Syria, saying relief workers and ambulances have come under fire on several occasions.
"It is completely unacceptable that volunteers who are helping to save other people's lives end up losing their own," said Beatrice Megevand-Roggo, the International Committee of the Red Cross' operations head in the region.
A Syrian Arab Red Crescent volunteer died week from injuries and two other volunteers were hurt after their ambulance was caught in heavy fire while transporting a wounded person to hospital, said the relief agency.