Dia al-Kawwaz, editor of Internet website Shabeqat Akhbar al-Iraq (Network of Iraqi News), said militiamen sprayed his relatives with bullets after storming into his house on Sunday.
"Four gunmen entered my family house in Shab area. Two of my sisters, their husbands and seven children between five and 10 years old were killed yesterday (Sunday) morning," Kawwaz told AFP on Monday by telephone from Amman.
He accused Shiite militiamen of carrying out the killings, saying they "stormed the house when the family was having breakfast".
"Earlier I was accused of being pro-US and so had to flee to Germany and now I am accused of being a Saddamist," said Kawwaz, a Shiite, who has lived in Germany for the past 20 years.