One protester was killed when Syrian security forces used tear gas and live ammunition against thousands of demonstrators who took to the streets Friday across the country.
The Syrian Observatory for Human Rights said that the protester was shot dead in the Mediterranean port city of Latakia, where hundreds of demonstrators were calling for overthrowing the regime.
Several people were injured.
Heavy gunfire was also heard in the Damascus districts of Hajar al-Aswad and Zahra, the group added.
Protesters turned out for the demonstrations that they had dubbed "Your Silence is Killing Us" - to protest against the relative silence from neighboring Arab countries to the Damascus government crackdown, as well as against Syrians who support President Bashar Assad.
"All countries condemned attacks in Norway, which left 90 people dead. In Syria, some 2,000 have been killed, but the Arab rulers and the Arab League remain silent," activists said in a Facebook message.
In the northwestern city of Idlib, around 15,000 people were protesting as snipers were deployed on the top of one of the main mosques in the centre of the city, activists said.
In the southern city of Daraa, security forces fired live ammunition and tear gas canisters against protesters. Several people were arrested, including two boys aged 13 and 14, activists said.
Around 10,000 gathered in Homs and in support of other provinces where recent crackdown left several killed, said the opposition group the Local Coordination Committees of Syria.
Protesters in the neighborhood of Karam al-Shami, in Homs, came under heavy fire by security forces. Several people were injured.
Local human rights advocates say that more than 1,500 civilians have been killed since anti-government protests began in mid-March in Syria. Over 350 security personnel have also been killed.
There is virtually no independent verification of such reports and figures, as Syrian authorities have barred most foreign media and international human rights groups from the country.
Protesters have called for daily protests during the Muslim holy month, expected to begin on Monday. Activists from Homs said that pro-democracy protests would be held every night in Ramadan and continue until dawn.
Ramadan is one of the holiest months in the Islamic calendar during which Muslims have to abstain from eating and drinking from dawn to sunset.
Syrians have recently intensified their protests against the 11-year-old rule of Assad despite a draconian clampdown by the security and army troops.
Meanwhile, a Syrian official said Friday that a "terrorist" attack had targeted an oil pipeline in Homs, which he said was located near a dam, which irrigates large tracts of farmland.
"This is primarily a subversive and terrorist act, aimed at two vital sectors," the official Syrian News Agency SANA quoted Ghassan Abdel Aal, the governor of Homs, as saying.
"The explosion caused heavy damage to the pipeline and disrupted the irrigation process as it caused oil pollution in the dam and irrigation canals," said Abdel Aal.
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