The father of a 21-year-old Tanzanian, who has been missing since Hamas militants attacked the kibbutz he was living on in Israel, has told the BBC of his anguish, naming his son publicly for the first time.

“The last time I spoke to Joshua was Thursday 5 October,” says his father Loitu Mollel. “I said ‘be on your best behaviour because you’re somewhere new, and make the most of the internship you’re there to do’.”

Two days later Joshua Mollel’s new home – Kibbutz Nahal Oz – was attacked by Hamas.

He had left his family’s place in northern Tanzania just the previous month.

Boarding the plane was a moment of excitement for Joshua.

Not only was this his first time travelling abroad – it was also a big step towards making his ambitions a reality.

“My son wants to make his fortune in agribusiness and become one of Tanzania’s most successful farmers,” his father says proudly.

He and his wife hope Joshua’s studies in Israel will eventually boost the modest incomes they make from teaching and growing crops.

Being the eldest child, Joshua’s younger brother and sisters look up to him as role model – so it hurts that they have not spoken to him on the phone for weeks.

On 7 October dozens of residents were massacred in Kibbutz Nahal Oz, and hostages taken over the border to Gaza which lies just 800m away.

Nobody knows what became of Joshua, and his family are sick with worry.

“We can’t eat or sleep – when I go to the market people ask me why I’m losing so much weight,” says his father.

“When the news came that Israel had been attacked by Hamas, I tried to find out if Israel had an embassy in Tanzania but I was told that they operate from Kenya.

“So instead I contacted the Tanzanian foreign ministry and I even contacted Tanzania’s ambassador in Tel Aviv.

“But I’ve still received no information about where my child is and in what condition.”

Neither Tanzania nor Israel have confirmed the identities of two Tanzanians students who are known to be missing.

But the BBC has worked to establish who they are, speaking to their families to confirm details about their lives.

We know that Joshua Mollel is one of the two missing students, and we know the identity of the other – but their parents have chosen not to name them publicly.

“We are working in support of the Israel authorities to find out where the two missing students are,” says Tanzania’s ambassador in Tel Aviv, Alex Kallua. “We can’t tell if they are held hostage or even otherwise because we are looking for the correct information.”

The BBC has also contacted Israel’s foreign ministry with a request for comment.

Some 350 Tanzanians live in Israel, 70% of whom are students mostly pursuing agricultural-related studies, according to Tanzanian officials.

Ambassador Kallua says nine Tanzanians have returned to their home country safely within the last week, and that his embassy staff are “keen to make sure that we are in touch with the other Tanzanians [who are still] in Israel and making sure all are safe”.

Joshua’s family says his internship at Nahal Oz’s dairy farm in Israel was organised by his college in central Tanzania, the Ministry of Agriculture Training Institute – Katrin. The college has not replied to the BBC’s request for comment.

“We do not want to stand and blame the authorities for the slow search for my grandson, because we understand some parts of Israel were attacked by Hamas,” Joshua’s grandfather, Ephata Nanyaro, says diplomatically.

But this does not lessen the family’s pain.

“He was last seen online on [the messaging app] WhatsApp on 7 October at around 10:00 [13:00GMT] in the morning,” recalls Joshua’s father.

“I’m so stressed… It is really difficult. My little girls ask me every morning and night – ‘Dad, we want to talk to our brother’.

“But I don’t have any answers to give.”