A Nigerian military official says about 700 people were killed in the northern city of Maiduguri during recent fighting between police and a radical Islamist sect.

The toll was previously thought to be around 300.

Col. Ben Ahanotu told The AP Saturday that mass burials have begun because bodies were decomposing in the heat. He says the Islamist compound destroyed this week by government troops is one of the burial sites.

The city was largely quiet Saturday, but sporadic violence continued. The fighting affected other northern cities, too. The total death toll is unknown.

Borno Police Commissioner Christopher Dega says the Boko Haram sect may be regrouping. Boko Haram wants to impose Islamic Shariah law. Troops killed the sect leader Thursday.