Some of those leaving are students after the university was closed.

The attacks have been carried out by the radical Islamist group, Boko Haram, which opposes Western education and fights for Islamic rule.

The security forces have been accused of firing indiscriminately and killing civilians after the raids. 

Boko Haram has carried out most of its attacks in Maiduguri but has also bombed targets in the capital, Abuja, in recent months. The BBC's Bilkisu Babangida in Maiduguri says the city is gripped by fear with many people staying indoors.

Correspondents say bus stops are overcrowded as the exodus from the city grows. Some people are leaving on foot with their belongings and livestock.

On Tuesday morning, a military patrol was targeted in Maiduguri and in the ensuing confusion, four people were shot dead and two soldiers wounded.There has also been a blast at a church in the town of Suleja, near Abuja.

No casualties have been reported.