At least 23 Afghan civilians were killed by militants during clashes in the country's Kandahar province within two days, a police official said on Friday.Hundreds of militants stormed remote Nash district in an effort to capture its control but the security forces repelled the attackers, leaving 29 militants dead," Xinhua news agency quoted the official as saying.He said six police personnel were also killed and four policemen wounded during the clashes."The Taliban sneaked into several houses in villages across the district and killed 23 civilians in retaliatory attacks," he said."A cleanup operation continues in the district," he added.The province is notorious for poppy growing and militancy.The Taliban militants have escalated attacks and have been on the rampage since April when they launched an annual rebel offensive in different places in Afghanistan, killing and injuring hundreds.More than 2,560 civilians were killed and over 5,830 injured in the first nine months of the year in conflict-related incidents across Afghanistan, according to the latest figures released by the UN mission in the country.Ground engagements remained the largest cause of civilian casualties, followed by suicide attacks and improvised explosive device explosions.