WALTHAM – Eversource crews are working to restore power to several Waltham neighborhoods after an "abnormal voltage issue" caused outages on Saturday.

Waltham Police said Saturday night electrical surges throughout the city caused transformer fires, traffic signals to fail and smoke in buildings

An Eversource spokesman said in a statement on Sunday that about 30 locations had meters and wiring damaged.

We have hired external electricians who are assisting us and the affected customers to exchange the meters and make repairs where we can. While we continue to investigate the root cause of this issue, we encourage any of these affected customers who are having trouble with their meters to call us at 800-592-2000.

As of Sunday morning, about 181 customers are without power as a result of 20 outages.