Paris - Twenty-eight civilians were killed and 13 were wounded in weekend massacres and bomb attacks, Algerian newspapers reported yesterday. A bomb explosion killed two people in Sidi Nadjdi area in the province of Medea, 70 km south of Algiers, on Saturday, Le Soir d'Algerie newspaper said. Twelve people, mostly schoolchildren, were wounded in the same province also on Saturday when the bus they were travelling in hit a roadside bomb.