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In this photo released by Ningxia Police Department, Ma Yongdong, a murder suspect, is seen Saturday, Oct. 19, 2013 in an undisclosed location in northwest China s Ningxia autonomous region. Chinese authorities on Friday captured Ma they suspect fatally stabbed his pregnant wife and six of her relatives, including two elderly grandparents and two young nieces on Oct. 14.
BEIJING—Chinese authorities have arrested a man suspected of fatally stabbing his pregnant wife and six of her relatives, including two elderly grandparents and two young nieces.

Police in China's northwest autonomous region of Ningxia announced the arrest of 24-year-old Ma Yongdong late Friday night on its official microblog.

State media said the suspect had quarreled Monday with his wife, Lan Xiaohong, who was six months pregnant. They said he found her later that day at her parents' home in a village in Pengyang county, and that he clashed with his in-laws before killing all seven victims with a knife.

The victims were Lan, her parents, grandparents and two nieces—ages 4 and 1 1/2.

To capture the suspect, Ningxia police set up a special work team, released photos of the man, and offered cash rewards up to 100,000 yuan ($16,000) for tips leading to his arrest.

Ningxia police said on their official microblog that Ma admitted to the homicides. They posted a photo of the handcuffed man as he was being interrogated and another photo of him being repatriated to Pengyang county.