The funerals of 17-year-old Kiea McCann and 16-year-old Dlava Mohamed have taken place in Co Monaghan and Co Dublin.
Friends and classmates of the girls, who were described as "soul friends", provided a guard of honour at the funeral services in both counties.
The teenagers were killed in a road crash outside Clones in Co Monaghan on Monday evening.
They had been travelling to a Debs ball at the time of the crash.
A hearse carrying Dlava's remains left Clones on Thursday morning and travelled to Clonskeagh Mosque in Dublin, where her funeral service was held.
When it arrived, her body was washed and shrouded according to Islamic tradition in five pieces of white cloth.
Her family then spent time with her in private until the funeral prayer, which began shortly before 2pm.
The service was led by Sheikh Hussein Halawa, who said the incident "shook the entire Muslim community and the entire people of Ireland".
Dr Ali Selim, of the Islamic Cultural Centre of Ireland in Clonskeagh, described Dlava's death as a "tragedy", adding that he expected the community to fully support the family during this difficult time.
"It's a very sad day, especially when you think of the circumstances of the (Mohamed) family," he said.
"They ran away from Syria because they didn't feel safe, looking for protection, and unfortunately the place where they thought they would be safe, they were hit with this tragedy."
In the Muslim religion, Dr Selim said, death is seen as a "step in our trip to our Lord". He offered his condolences to Dlava's friends and family.
Among the attendees were Deputy Principal of Largy College Michael Killen, Director of Schools at Cavan/Monaghan ETB Paddy Flood, Inspector Graham Tolan, a representative of Monaghan Garda Station, and the Taoiseach's aide-de-camp Commandment Claire Mortimer.
A number of students and staff members from Largy College were also in attendance.
A coach transporting family and friends of the teenager followed the cortege as it took the journey south for the service.
The hearse carrying Dlava left Clonskeagh Mosque by garda escort this afternoon. Her classmates formed a guard of honour as her coffin was carried out.
She was laid to rest in Newcastle Muslim Cemetery.
In Clones, hundreds of mourners walked behind the hearse carrying the remains of Kiea McCann to the Sacred Heart Church in the town.
Her family wore t-shirts, bearing a picture of the 17-year-old as they walked behind her coffin. Before entering the church grounds, motorcycles revved their engines as the cortège passed.
The funeral heard that Kiea was popular among her friends. Fr John Chester told the congregation that Kiea had a great sense of humor, was pleasantly mischievous and innocent.
The congregation heard how Kiea was "rarely off the iPhone, keeping in touch", and was someone who "kicked football with her close circle of friends, played pool, enjoyed music and the weekend discos".
"Kiea was kind, whole-hearted, genuine," he said.
Fr Chester spoke of how Kiea's father, Franky, responded to the scene of the crash on Monday night.
"Listening to him describe his frantic actions, following his arrival at the scene of the crash, he described conducting CPR on his daughter, and her soul friend Dlava, but with no success, the hands of the two girls touching as though they knew they were off to heaven together.
"No father should have to witness such a terrible scene," Fr Chester said.
Among the symbols presented at the funeral, include figures of Minnie and Mickey Mouse, an iPhone, a hair straightener and a photo taken of Kiea in her Debs dress on Monday night.
Earlier, a moment of silence was held for the two people who remain critically ill in hospital following Monday’s crash.
A candle was also lit in the Sacred Heart Church in Clones to represent Dlava. Kiea was laid to rest at Mount St Oliver's Cemetery.
Taoiseach Leo Varadkar has paid tribute to the two teenage girls.
Speaking in Cork, he said: "I really want to extend my condolences and sympathies to the McCann family, the Mohamed family, and the entire community in Clones and really everyone has been affected by this terrible tragedy.
"The debs is one of those special occasions in our lives, a rite of passage that marks the transition from being a school child to being a young adult, and it's a time filled with opportunity and boundless hope.
"And for these young lives to be cut short in such an untimely way, in such a tragic manner, I think has gripped the nation."
Mr Varadkar, who said one of his family members died in a crash in the past, also expressed his "best wishes" to those who are still in hospital, adding: "I hope they'll make a full recovery."
Largy College principal Sharon Magennis said the school community had been absolutely devastated by the incident.
She said that the friends and classmates of the girls were in shock and that the immediate aftermath of the tragedy has been "difficult beyond imagination".
Read more:
Hundreds form guard of honour for Dlava Mohamed
Guard of honour in Clones for Kiea Mcann
Ms Magennis paid tribute to the work of gardaí, especially Gerard Tolan, who she said helped the school coordinate its response to the tragedy.
She thanked the entire community for the support that has been offered.
Books of Condolence will be opened for Kiea and Dlava at Largy College tomorrow from 9am to 1pm.
Three other people were injured in the single vehicle crash on the N54 at Legnakelly on Monday evening.
Dlava's 18-year-old sister is in a critical but stable condition in Beaumont Hospital in Dublin.
A 60-year-old man, the driver of the car, was taken to the Royal Victoria Hospital in Belfast, where he remains in a critical condition.
An 18-year-old boy was treated for non life-threatening injuries and has since been discharged from hospital.
Additional reporting: Tommy Meskill; PA
