SANAA (AFP) - Yemeni tribesmen attacked an army camp near the capital Sanaa on Thursday sparking clashes in which dozens on both sides were killed or wounded, the military and tribesmen said. "Armed groups of hundreds" attacked an army post in Samaa, 40 kilometres (25 miles) northeast of Sanaa, the defence ministry news website,, quoted a military official as saying. A group of "criminal elements" infiltrated the camp while another group "shelled it, using various weapons," killing or wounding several soldiers, said the official. The army responded "and both sides clashed fiercely ... bringing massive losses" upon the attackers, said the official. Tribal sources confirmed casualties, saying that "dozens were killed and wounded" from both sides. The army called in air support against the tribesmen who took over part of a camp held by Republican Guard troops, loyal to embattled President Ali Abdullah Saleh, the tribal sources said.