MAIDUGURI, Nigeria, April 26 (Reuters) - Blasts and gunfire were heard on Thursday in the Northeast Nigerian city of Maiduguri, the city worst hit by the Islamist militant Boko Haram insurgency, witnesses said.

Witnesses reported a heavy military presence in the Jiddari Polo area of the city. The military issued a statement urging people "not to panic and discountenance rumours of Boko Haram presence".

Boko Haram militants attempted to enter Maiduguri earlier this month, clashing with soldiers in an attack that killed at least 15 people and left 83 injured. (Reporting by Ola Lanre, Ahmed Kingimi and Tife Owolabi in Yenagoa; Writing by Alexis Akwagyiram; Editing by Kevin Liffey)