Twenty-three people trying to cross the Mediterranean to Europe from Tunisia have been missing for the past two weeks, the country's National Guard said in a statement on Saturday.

The National Guard, which oversees the North African country's coastguard, said searches were still under way after the group departed in early May.

"They set sail overnight between May 3 and 4" from the city of Nabeul, the statement said, adding that relatives of the missing only contacted the authorities 10 days later.

Acting on orders from prosecutors in Nabeul, the National Guard said it had arrested five people allegedly involved in organising the crossing.

It said two of the missing were related to some of the organisers.

The National Guard also said it recovered four bodies later Saturday, after intercepting two crossing attempts to Europe and rescuing "52 migrants" near the city of Sfax, a main departure point for Italy.

The National Guard did not specify the nationalities of the bodies and the rescued migrants.

But a press release from the foreign ministry of Benin said that a "boat carrying some 50 migrants of various nationalities, including from Benin", had capsized "on the night of May 16 to 17 off Tunisian coasts".

"This shipwreck caused dozens of losses of human life still currently being assessed," said the press release, adding that searches were ongoing to "identify the bodies of the victims".

It remained unclear whether the shipwreck reported by the Benin authorities was related to the one Tunisia's National Guard said it intercepted.

Tunisia is a key departure point for irregular migrants who risk perilous sea journeys hoping to reach Europe.

More than 1,300 died or disappeared last year in shipwrecks, according to the Tunisian Forum for Social and Economic Rights (FTDES), a non-governmental organisation.

Last week, authorities reported a 22.5 percent increase in the number of migrant interceptions, with more than 21,000 people prevented from leaving Tunisia or rescued during the first four months of 2024.

According to the National Guard, 21,545 people were intercepted between January 1 and April 30, compared with 17,576 over the same period last year.

Since January 1, the bodies of 291 shipwreck victims have been recovered compared with 572 last year in almost triple the number of operations (1,967 this year against 686 in 2023).

Last year, Tunisians accounted for the second largest number of irregular migrant arrivals in Italy, at 17,304 people, second only to Guineans at 18,204, Italian government figures show.

The increase in interceptions comes after agreements between Tunisia and the European Union and Italy, who provide financial aid and economic cooperation deals in return for the debt-ridden country's commitment to curb migrant departures.

Tunisia has also been shaken by political tensions after President Kais Saied orchestrated a sweeping power grab in July 2021.