The first incident happened just after 7.30am today (Friday) and a second happened just before 10am which has caused a full closure of the M11 northbound between junctions 4 and 6.
Police and Highways Agency Traffic Officers are currently at the scene dealing with the incidents. Motorists are advised to avoid the area and allow extra time for their journey as there are delays in the area.
The motorway will fully reopen as soon as it is safe to do so.
The Highways Agency provides live traffic information via its website, local and national radio travel bulletins, electronic road signs and mobile platforms, such as the iPhone.
Members of the public should contact the Highways Agency Information Line on 0300 123 5000.
Journalists should contact the Highways Agency press office on 0844 693 1448 and use the menu to speak to the most appropriate press officer.