Forty fire fighters and officers from stations across East London have been called to the Lyons Business Park on River Road in Barking to tackle a well developed fire.
Six fire appliances and an aerial ladder platform have all been scrambled to the incident that broke out just after 2.30am on Wednesday morning.
Fire crews have been hampered in tackling the blaze in the two units due to the reinforced security doors on both business properties. Two hose reel four breathing apparatus are in use and a thermal imaging camera is also in use.
Officers from the Met Police have also been called to the incident and have established a scene and have blocked the entrance to the business centre.
The cause of the blaze in also under investigation.
A Police helicopter has also been called in to assist with fire fighter activities
More to follow
The LFB have been approached for comment