The soldier killed in an attack in London has been named as Drummer Lee Rigby of the 2nd Battalion the Royal Regiment of Fusiliers.
Drummer Rigby, 25, from Manchester, leaves behind a two-year-old son.
Two suspects shot by police after Wednesday's attack in Woolwich remain under arrest. A further two people have been arrested on conspiracy to murder.
The suspects, one of whom is said to be Islamist protester Michael Adebolajo, were known to security services.
Scotland Yard said the latest arrests were of a man and woman, both aged 29.
Drummer Rigby's family issued a statement on Thursday, saying: "Lee was lovely. He would do anything for anybody, he always looked after his sisters and always protected them. He took a 'big brother' role with everyone.
"All he wanted to do from when he was a little boy, was be in the Army.
"He wanted to live life and enjoy himself. His family meant everything to him. He was a loving son, husband, father, brother, and uncle, and a friend to many."