Human rights advocates on Friday reiterated their call for political leaders to ensure safe passage and end criminalization of rescue operations following reports that as many as 150 migrants drowned in a shipwreck in the Mediterranean Sea.

“This high number represents a new low for European leaders,” said Massimo Moratti, research director for Europe at Amnesty International, in a statement.

“They have done everything they can to pull up the drawbridge to Europe; withdrawing Search and Rescue Operations; criminalizing NGO rescue boats; cooperating with the Libyan coastguard, and yet people are still risking their lives to come to Europe.”

The United Nations refugee agency also stressed the need for swift action.

Speaking to reporters in Geneva on Friday, UNHCR spokesperson Charlie Yaxley said that the boat disaster “underscores once again the terrible urgency of our repeated pleas to European and other governments for restoring sea rescues and help with alleviating the suffering of the thousands of refugees and migrants caught in the conflict in Libya.”

The latest tragedy—the Mediterranean has been a graveyard of migrants for years—took place Thursday.

According to Reuters

“The worst Mediterranean tragedy of this year has just occurred,” said U.N. High Commissioner for Refugees Filippo Grandi in a tweet on Thursday.

One of the survivors, Abdallah Osman, told Agence France-Presse that the trouble began about 90 minutes into the trip when the boat began to take on water. Though a passing ship saw the boat in distress, it took no action.