The two students who were killed in a mass shooting at Brown University have been identified, as the hunt for the gunman continues two days after the attack.

Students Ella Cook and Mukhammad Aziz Umurzokov were killed on Saturday when a figure dressed in black opened fire in a lecture hall at the Ivy League university in Providence, Rhode Island. Nine others were injured.

A search for the suspect is back on, after officials released a previous “person of interest” on Sunday.

On Monday, investigators shared several short videos of the person they are now seeking. The videos revealed few details but showed a person all in black walking down a residential street shortly before the crime.

The announcement that a person of interest in the case was released and the fact that days after the attack no one has been arrested has put the community on edge.

Rhode Island Attorney General Peter Neronha said there was “no basis” to keep the first person investigators detained, adding that evidence “now points in a different direction”.

Authorities did not say what had prompted them to detain the individual.

FBI Director Kash Patel said his agency is offering a $50,000 (£30,000) reward for information leading to an arrest.

“We are in the 49th hour, and there’s no one that wants to put this individual in handcuffs more than us,” Providence Police Chief Col Oscar Perez told reporters at a news conference on Monday.

Videos released by authorities on Monday show a person wearing a black face mask. The person is also pictured wearing a dark jacket and pants, and a dark woollen cap.

In one video, the person walks past a fence. In another, they cross a street, and in a third they walk down a residential road.

All remaining in-person exams and classes for the semester have been cancelled at Brown University.

Patel said the person of interest who was released had been detained at a hotel in the town of Coventry in the early hours – based on a lead from Providence Police.

At that point, Col Perez said officers were not looking for anyone else and were working with prosecutors to collect evidence.

But later that evening, officials reversed course, and said the person in custody was not considered as a suspect.

On Monday, Perez declined to say whether any possible motive is known to police, and also declined to say whether any individual was specifically targeted by the gunman or if the suspect was shooting at the crowd at random.

The gunman opened fire in a classroom at around 16:00 local time (21:00 GMT) on Saturday at the Holley engineering building at the eastern end of Brown’s campus, according to officials.

Providence Mayor Brett Smiley said one of those injured in the incident was in a critical condition, while seven others remained stable and another had been discharged from hospital.

In a post on X, the College Republicans of America released a statement identifying Ella Cook as one of the deceased.

“We are devastated to learn of the loss of our Brown College Republicans Vice President Ella Cook,” the statement said.

“Ella was known for her bold, brave and kind heart as she served her chapter and her fellow classmates.”

White House Press Secretary Karoline Leavitt said on X about Ms Cook: “There are no words.

“Thinking of her family and friends, especially her parents. God please bless them.”

In a statement about the loss of Mr Umurzakov, a Uzbekistan national, the Uzbekistan Ministry of Foreign Affairs said: “The loss of innocent lives as a result of this tragedy is a heavy loss for all of us.”

The US ambassador to the country said he was “deeply saddened by reports of the tragic death”.

“We extend our sincere condolences to Mr. Umurzokov’s family, friends, and fellow students and mourn the loss of his bright future,” Ambassador Jonathan Henick said.

Mr Umurzokov’s aunt, Karina Gabit, told NBC News that he was an aspiring neurosurgeon who was “very kind, smart. Attended talented and gifted schools”.

In an email to staff on Sunday, the head of Durham Academy, a private school in North Carolina, said one of their alumna, Kendall Turner, was injured in the attack, US media reported.

“Our thoughts and prayers are with Kendall, her family, and all members of the Brown University community during this incredibly difficult time,” said Michael Ulku-Steiner.

In a statement released by the university on Sunday, Prof Paxson said some areas of campus were still restricted as police continued their investigations.

Around 2,000 students were relocated to safe locations overnight, she said, adding that she was “deeply moved” by students and locals who opened up their homes.

Prof Paxson said the families of the two students killed were being supported.

“There are not enough words of comfort for families who lose a child, but we will do all we can,” she added.

Smiley said an order for residents to shelter was lifted on Sunday.

The mayor said he had met with victims and their families in the hospital and was “overwhelmed” by their “courage, hope, and gratitude”.

On Sunday evening, the community gathered for a candlelit vigil honouring victims of the shooting.

Speaking at the White House, President Donald Trump said on Sunday that he hoped the nine injured students “get well fast” and paid respects to the families of the two people who died.

On Monday, he defended the FBI after the first person of interest was released, and no additional suspect was arrested.

The attack brings the number of mass shootings in the US to 389 this year, according to the Gun Violence Archive.

It defines mass shootings as having four or more victims killed or injured, not including the attacker.