A 40-year-old man and a 35-year-old woman have been arrested on suspicion of murdering a woman and her three children in Greater Manchester.
The family had not been seen for several weeks
Uzma Rahan, 32, and her children Adam, 11, Abbas, eight, and Henna, six, were found dead at their home in Cheadle Hulme on Sunday.
Police are still looking for the children's father, Rahan Arshad, 36.
Tests showed all four victims died from serious head injuries and police concluded they were beaten to death.
Det Supt Martin Bottomley said the 35-year-old woman was arrested on Wednesday morning. Officers later arrested a 40-year-old man.
The pair are thought to be a married couple from Burnage. A house in that area was sealed off on Wednesday as part of the inquiry.
Neighbours at Turves Road had raised concerns about the Arshad family after not seeing them for several weeks.
Police said the four victims may have been dead for up to four weeks.
Greater Manchester Police found Mr Arshad's BMW at Heathrow airport on Tuesday.
They believe he left the UK at the end of July and an international hunt is under way.
The British-born taxi driver may have gone to Pakistan, from where his family originate.
Det Supt Martin Bottomley, of Greater Manchester Police, said: "We are still actively looking for Rahan Arshad and I now believe he left the country around 29 July.
"We will be liaising with our colleagues on international police forces to help us to trace him.
Neighbours had raised concerns about the family
"I would ask anyone who has seen him or been in contact with him since 29 July to contact the incident room or any police officer immediately."
Although the bodies were formally identified by police on Wednesday night.
Mrs Rahan worked as a lunchtime canteen organiser at Lancasterian School in West Didsbury.
Julie Warren, assistant head teacher, paid tribute to her saying she was a "valued and respected member of staff".
The children's head teacher at Bradshaw Hall Primary School said staff and pupils were "shocked and saddened."
Jill Lowe said the siblings were "lovely, cheerful children" who were "a joy to teach".