Mobile networks bear blast calls
Vodafone, the largest network, told the BBC News website that it had seen "significantly higher call volumes" than usual following the incidents.
A spokesperson said Vodafone was advising people in London to avoid making unnecessary calls, and to send text messages instead.
Police have called for anyone with mobile images or video to e-mail them.
They have asked that anyone with images relevant to the incident should send them through the www.police.uk website, or send the photos via MMS (Multimedia Messaging Service) to 07734 282 288.
While some networks are noticing the increase in call traffic others, such as T-Mobile, told the BBC News website that it was still business as usual.
A spokesperson said that it was experiencing "none of the congestion" that it had faced two weeks ago.
A number of London Tube stations have been evacuated and lines closed after the minor blasts in what Met Police chief Sir Ian Blair says is a "serious incident".
They come just two weeks after four blasts, three on the London Underground system and one on a bus, killed 56 people.
A spokesperson from Orange there was a "slight increase" of calls made on the network directly after the latest incidents, but that levels were now back to normal.
The strain, he added, was "nowhere near" as significant as the levels it saw two weeks ago following the attacks.
O2 reported a high volume of calls in the London area following reports of the blasts. It too advised people not to make unnecessary calls.
Both Vodafone and T-Mobile said they had not received any requests from authorities to prioritise traffic or to shut down any part of the mobile network.
Directly following the incidents two weeks ago in London, mobile phone images and videos flooded into news websites, as well as blogs and photo sharing websites.