Police said one of the crashes involved seven vehicles, with a second incident seeing three trucks collide.
There is no word yet on casualties from the two pile-ups.
The closure of the northbound carriageway from junction 2 to junction 3 is expected to continue throughout the morning into the early afternoon.
It was shut off just before 2am this morning but has remained closed so police can investigate the two incidents.
Highways England said: “Drivers are being advised that the M6 northbound between junctions 2 and 3 around Coventry will remain closed through rush hour this morning following an earlier incident.
“The closure is expected to remain in place until late morning or early afternoon, with drivers being diverted off at junction 2 to take the A46 and the A45 around the south of the city and then re-join the M6 at junction 4.
“The M6 northbound was also closed earlier between junctions 1 and 2 following an incident at 2.40am involving a trio of lorries, with one hitting the safety barrier.
“Traffic has since been cleared with lane three (by the central reservation) opened and this stretch of the M6 is expected to fully re-open shortly (before the rush hour).”