At least two migrants have died and about 20 are missing after their boat sank between Tunisia and Italy, while another boat got lost in the sea between Libya and Malta.

The NGO's Nader rescued 22 migrants it transported on Sunday afternoon to the Italian island of Lampedusa, according to Steffen Seifert, an official with the German NGO Riskship, who said the migrant boat sank on Sunday night.

The captain of the rescue ship Ingo Wirth told AFP that among those rescued were men and women, including a pregnant woman and children from Cameroon, Ivory Coast and Mali, while the ship's crew recovered the bodies of two men.

Seifert added that a total of 40 migrants were on board when it left the coast of Tunisia's Sfax province. "We did everything we could to save more, but we didn't succeed," he said, referring to the "good cooperation" with the Italian coastguard.

According to the Italian news agency ANSA, among the survivors are 9 women, and the number of missing is estimated at 18.

The migrants are believed to have paid 3,980 Tunisian dinars (about $<>) each to take part in the migration journey, the agency said.

Lost boat between Libya and Malta

Meanwhile, the support service "Alarm Phone", which is active in migrant rescue operations in the waters of the Mediterranean, said on Sunday that a boat carrying about 400 migrants lost its way between Malta and Libya, while leaking water, amid a sharp rise in the number of migrant boats crossing the sea from North Africa.

🆘~400 persone in pericolo nel Mediterraneo!

Nella notte abbiamo ricevuto una chiamata da una barca in pericolo partita da #Tobruk, #Libia.
Abbiamo informato le autoritĂ , ma nessuna operazione di salvataggio Ăš stata confermata.
Non mettete a rischio 400 vite: soccorrete subito!

— Alarm Phone (@alarm_phone) April 9, 2023

The service added on Twitter that it had received a call from the boat that sailed from Tobruk in Libya last night, and that the service had informed authorities and said no rescue operation had been launched so far.

The boat's passengers were panicked and a number needed medical attention, Alarm Phone said, adding that the boat ran out of fuel and its base was filled with water while its captain left with no one on board to steer it.

Alarm Phone said the boat was currently in Malta's search and rescue area.