The pair were detained in Newport, Wales
Two more men have been arrested in Wales over the London Underground terrorist attack, police say.
The pair, aged 48 and 30, were arrested in Newport just after 5.00am.
It followed the arrest of a 25-year-old man in the city on Tuesday night after a counter-terrorism raid.
Police are continuing to search two properties in Newport.
The latest arrests bring the number of people being held over Friday's bomb attack to five.
Two other men, aged 18 and 21, are still in custody in connection the attack at Parsons Green in London.
Detectives were earlier given more time to question the pair arrested at the weekend.
Yahyah Farroukh (21) is listed as living at an address in Stanwell, Surrey, which was searched by officers on Sunday.
The 18-year-old man, who was arrested in Dover, is suspected of planting the device, which exploded on a District line train shortly after it pulled into the station.
Magistrates have granted warrants allowing Farroukh to be held until Thursday, and the younger suspect until Saturday.
The news came as CCTV footage emerged which appears to show the Parsons Green bomb suspect on his way to plant his homemade device.
The video shows a figure dressed in grey carrying a white supermarket carrier bag about 80 minutes before the blast.