NEW : Death toll in minivan explosion rises , government official says . Syrian rebels first overran the Syrian border gate at Bab el Hawa last summer . The rebel group has since taken over several other crossings into Turkey and is now threatening to take control of all land borders with Syria. Meanwhile , Syrian rebels claim to have captured Syria 's largest man-made dam .
NEW : Death toll in minivan explosion rises , government official says . Syrian rebels first overran the Syrian border gate at Bab el Hawa last summer . Turkish officials have not yet commented on the cause of the blast . Meanwhile , Syrian rebels claim to have captured Syria 's largest man-made dam .