A Metropolitan Police spokesperson confirmed a police operation was underway in the area.
Officers stormed the addresses in Barking and Newham at 4.15am this morning and confirmed "a number" of arrests have been made.
Police vehicles were pictured parked outside the Ship and Shovel pub in Barking.
Searches were continuing at both addresses, according to police.
The news comes hours after police stormed a flat in Barking connected to the London Bridge attack
Detectives in plain clothes are also at the scene, according to Sky News.
Transport for London has confirmed the A13 has been shut down between the Goresbrook Interchange and Lodge Avenue Flyover while police attend the scene.
According to local residents on social media, armed officers were followed by a helicopter escort as they moved in on the flat.
Scotland Yard have confirmed that a "number" of people have been arrested.
The raid comes amid an investigation into the London terror attack on Saturday London terror raids Sun, June 4, 2017
Police have raided a block of flats in Barking in connection with last night's London Bridge terror attack.
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As police continue their investigations following the June 3 terror attacks, a block of flats in Barking is raided for possible suspects
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One Twitter user wrote: “A loud noise like an explosion has woke me up out of my sleep followed by like gun shot sounds. Anyone else in Dagenham?”
Another wrote: “Gunfire and explosions in Dagenham? Helicopters are out too. Not the wake up I was expecting.”
A Scotland Yard spokesman said: "At around 4:15am on Monday, 5 June, officers from the Met’s Counter Terrorism Command investigating the London Bridge terror attack entered two further addresses – one in Newham and another in Barking.
"A number of people have been detained and are at present being spoken to.
"Searches are ongoing at both addresses."
The operation comes hours after police stormed a flat in Barking, east London, as part of an investigation into the London terror attack which left seven people dead and dozens injured on Saturday evening.
Morning after London attack: Heightened police presence at Borough Market & Bridge Sun, June 4, 2017
SIX people have been killed after a horrific terror attack targeted London Bridge and Borough Market on Saturday night. These are the pictures are London wakes up to the tragic scenes
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A vigil will be held for Londoners at Potters Field Park today at 6pm
Police arrested 12 people Sunday in connection with the incident from at least two addresses in Barking.
Seven women and five men were detained by armed police as they hunted for associates of the London Bridge attackers.
Theresa May said in a speech outside Downing Street yesterday that “enough is enough” and Britain must do more to combat the threat of terror.
Labour leader Jeremy Corbyn, however, blamed Mrs May’s swingeing police cuts for the UK’s susceptibility to terror attacks, and told the prime minister national security cannot be maintained “on the cheap”.