Pope Francis spoke of his “profound shock and sadness” on Saturday after 16 people were shot dead, including four Catholic nuns, at a home for the elderly in Yemen.
The Argentine pope said that the attack in Aden on Friday was an “act of senseless and diabolical violence.”
The BBC reports that the attackers pretended to be visiting their mothers to get into the home.
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Although no group has claimed responsibility for the bloodbath, Yemeni officials reportedly believe the slaughter to be the work of the Islamic State group.
The Vatican released a statement saying that two of the nuns killed were Rwandan, one was Indian, and the final one was from Kenya.
Pope Francis "prays that this pointless slaughter will awaken consciences, lead to a change of heart, and inspire all parties to lay down their arms and take up the path of dialogue", Vatican Secretary of State Pietro Parolin said.
A family member of one of the fatalities told AP that the victims were shot in the head, execution style, having been handcuffed.
More than 6,000 people have been killed and 2.4 million people displaced in Yemen's war, the United Nations reports.
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