An Iraqi pharmacist just back from his studies in the United States was among at least 18 people killed in a spate of attacks across the country over the weekend, officials said on Sunday. More than 20 other people were wounded in the violence, the latest in a surge of killings in August and as Muslims observe the holy dawn-to-dusk fasting month of Ramadan, when insurgents typically step up their attacks. The escalation has fuelled security concerns at a time when the United States aims to withdraw thousands of troops by the end of August, when it declares an end to combat operations in Iraq. Mohammed Ali al-Deen, who returned less than a month ago after completing a pharmacy course in Washington DC, was gunned down late on Saturday at his home in Noamaniyah in the central province of Wasit, a police officer said.