A fourth person has been arrested by police investigating the fatal shooting of an Indian student.
Anuj Bidve, 23, was gunned down at point-blank range as he walked with friends near their hotel in Salford, Greater Manchester, in the early hours of Boxing Day.
Greater Manchester Police (GMP) said today that a second man had been arrested.
Another man was arrested last night while two boys, aged 16 and 17, are also being held on suspicion of murder.
All four remain in custody for questioning.
Last night Mr Bidve's family paid tribute to a "loving son".
In a statement issued through GMP, they said: "Anuj was a loving son, a super caring brother and first and forever a friend for many.
"He valued his relationships and put them over anything else. He was the first person you could call when in trouble.
"Anuj loved to travel and loved his food. He loved to cook.
"He could easily bring a smile on anyone's face with his innocent jokes.
"He loved playing football. He enjoyed his time and life and is an inspiration for us to live life to its fullest.
"His passing will not only leave a void in our lives, but in the hearts of all those who knew him."
Mr Bidve, who was studying for a micro-electronics postgraduate qualification at Lancaster University, was part of a group of nine male and female Indian students visiting Manchester for a short break over the Christmas holidays.
Police said the students, who had not been drinking, were walking from their hotel towards the city centre and became aware of two men on the other side of the street.
The gunman, a white male in his 20s who was wearing a grey top, walked across the road and engaged the victim in a short conversation before producing the gun and shooting the student at close range to the side of the head.
The killer then ran back across the street before the pair fled on foot towards Asgard Drive and the Ordsall housing estate.
Armed response units were sent to the scene at around 1.35am and armed police remained on patrol there last night.
Mr Bidve, from Pune, Maharashtra, collapsed to the ground and died in hospital a short time later.
Speaking from Pune yesterday, Rakesh Sonawane, 30, who is married to the student's sister Nehal, said the devastated family had "lost faith in everything".
Mr Bidve arrived in the UK in September after completing an electronics degree at Pune University.
"Anuj had been very happy. It was his dream to go to the UK but unfortunately his dream could not last longer than three months," Mr Sonawane said.
He added that his brother-in-law had planned to return to India "to serve his nation" following his postgraduate studies in Lancaster.
Mr Bidve was described as "clever and sporty", and a fan of football, supporting Manchester United.
Mr Sonawane added that the family have received lots of messages of support, especially from the Indian student community in Lancaster.
They have spoken to some of those who were with Mr Bidve when he was killed and said the eight students have now returned to the university.
Tributes have been left on Facebook, including one page set up by a fellow Lancaster student which plans a "peace march" in the young man's memory.
According to the page, set up by Sonakshi Saran, Mr Bidve "was killed for not answering a simple question - 'What's the time?"'
GMP have not disclosed what was said during the short conversation between the killer and his victim.
The student's father, Subhash, a branch manager with an energy company, has called on the UK Government to speed up the process of returning his son's body to his home country.
In a message on his son's Facebook wall, he said: "Please help in getting Anuj Bidve's dead body back to India. He was shot in Manchester today morning. We appeal to all his friends in UK and India to help spread the word. Please help us get Anuj back. Please share this message."
Mr Sonawane said he had tried to contact the Indian High Commission in London but it has been shut for Christmas.
Professor Bob McKinlay, deputy vice chancellor of Lancaster University, said it will offer Mr Bidve's family help with the costs of repatriation of the student's body.
GMP said it was an "awful" attack and pledged to "leave no stone unturned" in the hunt for the killer.
Chief Superintendent Kevin Mulligan, divisional commander for Salford, said yesterday that a racial motive for the killing was not being ruled out, adding: "We are investigating every possible aspect."
Anyone with information is asked to call the incident room on 0161 856 5448 or Crimestoppers on 0800 555 111.