One of only four survivors after an inflatable raft carrying more than 80 people capsized off the coast of Tunisia has recounted his ordeal as 54 rescuees from a separate shipwreck headed to Malta.

Soleiman Coulibaly, from Mali, said he had spent two days clinging to a piece of wood after the engine caught fire and the inflatable sank.

“People were terrified as water started pouring in, some of them fell into the water. They stayed down there,” he told Agence France-Presse. Coulibaly said those on the boat included one woman with a baby and another who was pregnant.

According to survivors, the boat started to leak a few hours after their departure from the Libyan town of Zuwara, west of Tripoli on Monday.

Three Malians and an Ivorian were rescued off Zarzis in southern Tunisia on Wednesday by the coastguard, which had been alerted by local fishermen.

Coulibaly told the International Organization for Migration representative for southern Tunisia, Wajdi Ben Mhamed, he survived by “clinging to a piece of wood” before he was brought to safety.

“He doesn’t know what happened to the others. They’re missing and there’s a high probability that they drowned,” Ben Mhamed said.

Meanwhile, the rescue vessel Alex operated by the Italian NGO Mediterranea rescued 54 migrants in a separate incident off Libya. The boat is now heading to the port of La Valletta in Malta, where the Maltese government has allowed them to disembark.

In neighbouring Libya, at least 44 migrants were killed and more than 130 wounded on Tuesday night in an airstrike that targeted a hangar in a detention centre in the Tripoli suburb of Tajoura.

Libya’s government is considering closing all migrant detention centres in the wake of an airstrike that killed 53 people after it was reported that guards shot at detainees trying to flee the attack.

Overnight on Wednesday, the air force of Gen Khalifa Haftar kept up its bombardment of the Libyan capital, Tripoli, mounting raids on the international airport.

The UN high commissioner for refugees (UNHCR) meanwhile called for the evacuation of all the migrants held in the detention centres. The UN has also called for an independent inquiry into the bombing of the Libyan detention centre and described the attack as “a war crime and odious bloody carnage”.

“Such an attack deserves more than condemnation. UNHCR and IOM believe a full and independent investigation is required to determine how this happened and who was responsible, and to bring those individuals to account,” the UNHCR said in a statement.

The World Health Organization in Libya tweeted on Friday that since the beginning of the clashes in Tripoli on 4 April, nearly 1,000 people have died and more than 5,000 have been wounded. It called for a ‘‘quick and peaceful solution’’ for the safety of all people in Libya.