Pope Francis has condemned the killing of 16 people, including four Catholic nuns, at an old people's home in Yemen.
He called Friday's gun attack in Aden an "act of senseless and diabolical violence".
Reports said the attackers pretended they were visiting their mothers to gain access to the home.
No group has claimed responsibility for the attack, though Yemeni officials have blamed so-called Islamic State.
In a statement, the Vatican said two of the nuns killed were Rwandan, one was Indian and one was from Kenya.
'Pointless slaughter'
They were working as nurses at the home and had been serving breakfast to its 80 residents when the attack occurred.
All the victims were shot in the head and had been handcuffed, the Associated Press reported, citing the brother of a victim.
The nuns were from the Missionaries of Charity congregation, which runs the home and was founded in Calcutta by Mother Teresa.

Islamabad