Somerville has told Bird Rides, Inc. to suspend its service in the city, joining neighboring Cambridge in cracking down on the rentable electric scooters that appeared on public streets without permits this month.

In a letter to California-based Bird on Tuesday, Somerville City Solicitor Francis Wright, Jr. said the city will seize any scooters that are not removed by Friday.

Cambridge officials told Bird to pull out of their city during an hour-long meeting on Monday and threatened to impound scooters or sue the company.

"We haven’t decided exactly how quickly we intend to move on any action against Bird, but I expect it would be relatively quick since we don’t want to go too much longer without addressing the current situation," Cambridge Transportation Director Joe Barr said in an interview.

So far, Bird has not complied with the orders of Cambridge or Somerville — nor has it agreed to do so.

"We have been having productive conversations with local leaders and look forward to continuing those conversations in order to build a framework that supports affordable and equitable transportation options for the whole community," the company said in a statement Tuesday.

Conflicts with individual cities could be the least of Bird’s worries. Cambridge officials contend the company's scooters may be illegal throughout Massachusetts because they appear to violate a state law requiring “operational stop and turn signals so that the operator can keep both hands on the handlebars at all times.” Bird scooters feature neither blinkers nor brake lights.

Cambridge cited the possible violation of that law, among other reasons, when it ordered Bird to suspend its service.

The state's top law enforcement official, Attorney General Maura Healey, has so far declined to weigh in on the scooters' legal status.

Cambridge classifies Bird as a street vendor — same as a hot dog stand or T-shirt hawker — because it displays its scooters on public ways and charges people to use them. Street vendors need permits. The company doesn’t have one.

To obtain a street vendor permit, Bird would need approval from the Cambridge City Council. Barr said the city would not issue a permit unless the scooters comply with state law, but added that Cambridge hopes to reach an agreement with Bird that would enable the scooters to operate legally.

Somerville said in a statement that it "will be working on a policy and procurement framework in the coming months to invite formal proposals from potential scooter companies wishing to operate in Somerville."

Earlier this month, Boston Mayor Marty Walsh warned Bird to keep its electric scooters out of the city.