Parts of the recently introduced measure are unrelated to migration, but instead focus on "public order and security", increasing penalties for assault on members of the security forces and envisaging fines of up to 6,000 euros ($6,700) for people who hide their faces to avoid being identified during political demonstrations.
But the decree, which was championed by far-right Interior Minister Matteo Salvini, also gives additional power to the Ministry of the Interior on issues of migration, and mandates that ships which "ignore bans and limitations" on entering Italian waters will be seized.
The captain and crew could also be hit with fines of up to 50,000 euros ($56,000).
The UN refugee agency (UNHCR) warned last week that the new rules violate the rights of migrants and rescuers alike, saying that "no vessel or shipmaster should be at risk of a fine for coming to the aid of boats in distress and where loss of life may be imminent" and that "no-one should be returned to Libya". Despite the criticism, Italian President Sergio Mattarella signed the bill on Friday, meaning that the law is now in force.
"Saving lives is not a crime," Claudia Lodesani, president of medical NGO Doctors Without Borders Italy, told Al Jazeera. "It is a legal obligation that EU member states should make a priority. But, once again, Italy shows little sensitivity to international obligations."
Italy's governing coalition between Salvini's far-right League and the populist Five Star Movement has repeatedly denied NGO rescue ships access to Italian ports, leaving migrants stranded at sea for weeks. Salvini, especially, has described NGO ships as "sea taxis" and accused charity workers of working with human traffickers.
Threats of confiscations, fines and legal investigations have caused most NGO boats to abandon their work in the Mediterranean.
"It's hard to see the rationale for punishing search and rescue at sea," said Matteo Villa, of the Italian Institute for International Political Studies (ISPI). "Especially since arrivals by sea have shrunk so drastically."
According to data released by the interior ministry, 2,144 migrants arrived in Italy by sea between January 1 and June 10, 85 percent fewer than those who arrived in the same period in 2018, and 96 percent fewer than the year before.