Authorities are reporting that peace and quiet have returned to a populous Reynosa following reports of a shootout and grenade explosions.

Reynosa residents reported gunfire, grenade explosions and a helicopter flying overhead in the Cumbres neighborhood.

CIty officials confirmed a "situation of risk" in the Cumbres and Jardines Coloniales neighborhood around 3:14 p.m. Sunday.

Residents turned to the social newtork Twitter to report soldiers, a chase and a blockade on a highway linking Reynosa to Matamoros and Monterrey.

City officials lifted the alert around 4:14 p.m. Sunday.

Mexican military officials have not released a statement about the incident.

Cumbres is a populous neighborhood sandwiched between two highways that run through south and central Reynosa.