Muhammad Yunus has been sworn in as head of a new caretaker government in Bangladesh in a ceremony that began with a minute’s silence to remember those who were killed in the recent protests.

The swearing-in, led by President Mohammed Shahabuddin, was attended by more than 1,500 guests including politicians, students, protest coordinators and representatives from the military and civil society. Other members of the interim government also took their oaths.

Earlier, the entrepreneur and Nobel laureate had given an emotional speech to waiting reporters at Dhaka airport on his arrival in the country to take up his position.

Yunus said he hoped to restore calm and rebuild Bangladesh after the uprising that ended the 15-year, increasingly autocratic rule of the former prime minister Sheikh Hasina.

Yunus landed at Dhaka’s Hazrat Shahjalal international airport on Thursday afternoon after a trip to France for medical treatment. He was welcomed by Bangladesh’s military chief, Gen Waker-Uz-Zaman, who was flanked by leaders of the navy and air force. Some of the student leaders who led the uprising against Hasina were also there. They had proposed him as interim leader to President Shahabuddin, who is acting as chief executive under the constitution.

Security was tight at the airport as Bangladesh continues to experience unrest after Hasina resigned and left the country on Monday. Shahabuddin will preside over the oath-taking ceremony on Thursday night, when Yunus is expected to announce his cabinet. In his speech, he addressed the people of Bangladesh as “one big family” and said the young protesters had given them a “new birth” but he condemned the last two days of violence directed against the country’s religious minorities.

“My first word to you is to protect the country from disorder. Protect it from violence so we can follow the path our students have shown us,” he said, before paying an emotional tribute to Abu Sayeed, a 25-year-old student who was shot dead by police during a protest in Rangpur on 16 July. Yunus fought back tears as he described Sayeed as “an incredibly brave young man”.

Hasina’s son Sajeeb Wazed Joy, who acts as an adviser to his mother, had vowed on Wednesday that his family and the Awami League party would continue to be engaged in Bangladesh’s politics – a reversal from what he had said earlier on Monday, when he called the students “very ungrateful”.

Yunus was named as interim leader after talks among military officials, civic leaders and the student activists who led the uprising against Hasina.

Zaman, the military chief, said in a televised address on Wednesday he expected Yunus to usher in a “beautiful democratic” process.

Yunus, who was awarded the 2006 Nobel Peace prize for his work developing microcredit markets, told reporters in Paris: “I’m looking forward to going back home and seeing what’s happening there, and how we can organise ourselves to get out of the trouble that we are in.”

Asked when elections would be held, he put his hands up as if it were too early to say. “I’ll go and talk to them. I’m just fresh in this whole area,” he said.

A tribunal in Dhaka earlier on Wednesday acquitted Yunus in a labour law violation case involving a telecommunications company he founded, in which he was convicted and sentenced to six months in jail. He had been released on bail in the case.

Yunus has been a longtime opponent of Hasina, who has called him a “bloodsucker” allegedly for using force to extract loan repayments from rural poor, mainly women. Yunus has denied the allegations.

In the weeks since 15 July, more than 300 people have died in violence in Bangladesh. Rising tensions in the days surrounding Hasina’s resignation created chaos, with police leaving their posts after being attacked. Dozens of officers were killed, prompting police to stop working. They threatened not to return unless their safety was ensured. The looting of firearms was also reported in local media.

The chaos began in July with protests against a quota system for government jobs that critics said favoured people with connections to Hasina’s party. But the demonstrations soon grew into a broader challenge to Hasina’s 15-year rule, which was marked by human rights abuses, corruption, allegations of rigged elections and a brutal crackdown on her opponents.

Joy, Hasina’s son, said in a social media post on Wednesday that his family would return to politics and not give up after attacks on the Awami League party’s leaders and members. Many saw Joy as Hasina’s successor in Bangladesh’s dynastic political culture.

On Monday, Joy had said Hasina would be retiring to spend time with her grandchildren . But in a video message posted on his Facebook page on Wednesday, he urged party activists to rise up. “You are not alone. We are here. The family of Bangabandhu has not gone anywhere,” he said.

Hasina’s father, the independence leader Sheikh Mujibur Rahman, is fondly referred to in Bangladesh as Bangabandhu, which means “friend of Bengal”.

Joy said: “If we want to build a new Bangladesh, it is not possible without the Awami League. The Awami League is the oldest, democratic, and largest party in Bangladesh. The Awami League has not died … It is not possible to eliminate the Awami League. We had said that our family would not engage in politics any more. However, given the attacks on our leaders and activists, we cannot give up.”

Overnight into Thursday, people across Dhaka carried sticks, iron rods and sharp weapons to guard their neighbourhoods amid reports of robberies. Loudspeakers in mosques were used to alert people that robberies were occurring, and students formed volunteer groups to protect temples and businesses as police remained off duty. The military shared hotline numbers for those seeking help.

Many, including in neighbouring India, fear more instability in the densely populated country of 170 million people, which is already dealing with high unemployment, corruption and a complex strategic relationship with India, China and the US.

Hasina, 76, was elected to a fourth consecutive term in January, in an election boycotted by her main opponents. Thousands of opposition members were jailed before the vote, and the US and UK denounced the result as not credible.