Italian defense minister criticized the EU after up to 170 migrants are feared dead when two separate dinghies sank in the Mediterranean Sea.
"EU can no longer stand and watch," Elisabetta Trenta said in a Twitter post late Saturday.
One of the vessels capsized off Libya while another went missing near Morocco.
The UN's refugee agency said it was "deeply saddened" over the incidents, adding that the agency has yet to verify the death toll.
Maria Elisabetta Casellati, the head of Italian Senate, told reporters that they can't accept the death of so many innocent people, saying: "The Mediterranean must be the sea of peace, not a mass grave."
Italian President Sergio Mattarella also expressed his "deep sorrow for the tragedy that has taken place in the Mediterranean."
The Sea Watch charity organization said on Saturday that it had rescued from a rubber boat some 47 people -- including eight minors -- off Libya.
Pope Francis, during Sunday's church service, also expressed sorrow and prayed for the drowned victims.
He said he felt the pain of those who drowned while looking for better lives, adding that they were "victims, perhaps, of human traffickers".
The International Organization for Migration (IOM) estimates that last year more than 2,200 migrants died or went missing trying to cross the Mediterranean.
