NICOSIA (AFP) - Syrian army tanks rolled into more northwestern villages on Wednesday, as hundreds of lawyers staged a sit-in protest in the second city of Aleppo, a human rights activist said. "Tanks and troop carriers entered the villages of Mar-Ayan and Ihsem. They are currently at the outskirts of Al-Bara," a hamlet known for its Roman remains, said Rami Abdel Rahman. "The soldiers are deployed in the villages and are conducting searches," Adbel Rahman, who heads the London-based Syrian Observatory for Human Rights, told AFP in Nicosia on the telephone. The Observatory says 1,342 civilians have been killed since mid-March in a crackdown by President Bashar al-Assad's regime on pro-democracy protesters and that 342 security force personnel have also died. On Tuesday, the army had entered the village of Al-Rami, which is just off the highway leading to Aleppo, an economic centre where 300 lawyers organised the sit-in at the courthouse Wednesday. The lawyers chanted slogans for liberty and the release of political prisoners, while other, pro-regime lawyers also staged a sit-in in a different room in the courthouse. Abdel Rahman said a leader of the opposition Socialist Union Party was arrested in Aleppo on Tuesday evening, while a prominent member of Kurdish opposition party was detained in Al-Hasakah in the northeast. Pro-democracy activists on Facebook have called for a rally in Aleppo on Thursday. "Revolutionaries, come to Aleppo and Idleb provinces... and go to central Aleppo tomorrow, Thursday, to protest and to light the spark of the Revolution," he said. Elsewhere, on Tuesday night, between 50,000 and 60,000 protesters marched through the eastern town of Deir Ezzor, where demonstrations have become a daily event. The demonstrators called for the fall of the regime and chanted pro-liberty slogans. Meanwhile, author and activist Munzer Khaddam, who on Monday presided over a public meeting of opposition figures in Damascus, was taken to task by pro-regime supporters, activists said. More than 150 loyalists gathered outside Khaddam's Latakia home on Tuesday night and chanted "insults and slogans against liberty and the Damascus meeting," said Abdel Rahman. The chants at the counterprotest, which another activist also said had taken place, were aimed at opposition figures who vowed Monday to press ahead with a peaceful uprising at a meeting in Damascus.