After suicide attempts, fights erupting on board, and migrants jumping into the sea, charity SOS Mediterranee launched an emergency alert on Friday, demanding to be allowed to immediately disembark at a safe port.

The humanitarian group, whose vessel the Ocean Viking has been at sea for over a week with 180 migrants aboard, said it could no longer guarantee the safety of the migrants or crew and called a state of emergency in an unprecedented step.

The boat, which has been in limbo in the Mediterranean south of Sicily, has been waiting for over a week for permission from Italy or Malta to offload the migrants at a safe port.

Tensions have risen in the past week, as witnessed by an AFP reporter aboard the boat, as migrants have become increasingly desperate to reach land. Others have become distraught not being able to telephone their families to let them know they were safe.

A member of the crew, Ludovic, told AFP he had never witnessed such violence on board a rescue vessel, after a spate of fights between migrants and threats of suicide.

"I don't feel safe," Ludovic said. "We have to find a port now, it's a question of safety."

In limbo off Lampedusa In limbo off Lampedusa Photo: AFP / Alessandro SERRANO

SOS Mediterranee said in a statement it was not safe to keep migrants languishing on a boat after they had "endured a near-death experience on an unseaworthy dinghy in distress."

The migrants, which include Pakistanis, North Africans, Eritreans, Nigerians and others, were picked up after fleeing Libya in four separate rescues by the Ocean Viking on June 25 and 30, after setting sail from Marseille on June 22.

The migrants include 25 minors, most of whom are unaccompanied by adults, and two women, one of whom is pregnant.

"After seven requests for a Place of Safety to the relevant maritime authorities within the past week and six suicide attempts by survivors within 24 hours, the Ocean Viking has declared a State of Emergency..." the group wrote.

Early on Friday, a migrant tried to hang himself, the group said. Others exhibit "signs of extreme mental fatigue, depression and acute agitation which has erupted into several physical fights among the survivors on deck," SOS Mediterranee said.

Two migrants were rescued after jumping off the ship Two migrants were rescued after jumping off the ship Photo: AFP / Shahzad ABDUL

Meanwhile, two migrants had begun a hunger strike, said the group.

On Friday afternoon, the charity asked for a medical evacuation for 44 Tunisians, Moroccans and Egyptians showing signs of "acute psychological distress" who were threatening to harm themselves and others.

Italy responded with the telephone number of a psychologist, SOS Mediterranee said.

At times, all the members of the SOS Mediterranee rescue team have been on deck in order to calm tense situations. Now, some of the threats are being directed at the rescuers themselves.

Rumours abound among the groups of migrants, including that the NGO is in cahoots with Italian authorities, earning money each day the migrants are kept on board.

On Thursday, two migrants threw themselves into the Mediterranean, but were rescued.

The charity group said it had received a negative response from Italy and Malta after its first request for a port, and no replies to its six subsequent requests.

Nicholas Romaniuk, in charge of rescue operations on board, said there was no "legal or moral" reason to keep the migrants on board.

"It's Malta who alerted us and gave us the position of one of the boats in distress and now they don't answer the phone," Romaniuk said.

More than 100,000 migrants tried to cross the Mediterranean last year with more than 1,200 dying in the attempt, according to the International Organization for Migration.

The arrival of summer and more favourable conditions at sea may lead to an increase of attempts to cross the Mediterranean with the hope of arriving in Europe.