Several migrants jumped into the sea from a Spanish rescue boat in a bid to reach shore in Italy.
Crew members, however, jumped in and brought them back aboard.
"Nine people have thrown themselves into the water trying desperately to reach the coast of Lampedusa," the ship Open Arms tweeted. "The situation is out of control."
Open Arms, with almost 100 migrants onboard, has been left stranded just off the port of Lampedusa after Italy denied permission from entering its waters.
Earlier, Italy's hard-line interior minister, Matteo Salvini, banned private rescue ships, saying they have become "taxis" for people smugglers.
“If the worst happens, Europe and Salvini will be responsible,” the charity said in a tweet.
The US Department of Homeland Security is sending "hundreds" more officers to Minnesota, Homeland Security Secretary Kristi Noem said in remarks that aired on Sunday, after tens of thousands of people marched through Minneapolis to protest the fatal shooting of a woman by an immigration agent.
The US military said on Saturday it carried out multiple strikes in Syria targeting ISIS as part of an operation that Washington launched in December after an attack on American personnel.
Israeli fire killed at least three Palestinians in two separate incidents across Gaza, local health authorities said, as tension rises over continued violence.
Tens of thousands of people marched through Minneapolis on Saturday to decry the fatal shooting of a woman by a US immigration agent, part of more than 1,000 rallies planned nationwide over the weekend against the federal government's deportation drive.