Transportation agencies in the Washington region–and across the U.S.–are bolstering security following Friday’s terrorist attacks in Paris, and an Islamic State video released Monday that threatens a “Paris-style” attack on the nation’s capital.

The Washington Metropolitan Transit Authority said Monday it is expanding random screenings for explosives at station entrances and adding officers across the system. Amtrak and the Maryland Transit Administration are also taking extra security measures, while the New York subway system announced a “heightened state of alert” over the weekend.

Officials with Washington area airports said they are working with federal agencies to step up necessary security.

In Washington, Metro says any bags or packages brought into the system are subject to screening by officers. The transit agency says riders should expect to see additional police patrols system-wide for an unspecified period of time. The larger police presence went into effect Friday evening, the night of the attacks, the Transit Police said.

Riders already had a brief scare over the weekend, when a man slashed a woman with a knife outside the Union Station Metro entrance about 8:15 Saturday night, prompting a large emergency response. In that incident, an off-duty police officer shot the suspect and a bystander was struck by a ricocheting bullet. Police said terrorism was not involved.

MTP said its officers also will be conducting additional K9 sweeps as part of the heightened security. The department says it has more than 20 K9 teams that perform security sweeps in Metro stations and other areas across the system.

Amtrak said Monday it also is maintaining “strong security” to keep passengers, employees and the railroad safe.

“Extra K9, uniform personnel and long guns have been deployed,” Amtrak spokeswoman Kimberly Woods said. “We have reminded Amtrak employees to look for and report any suspicious activity and unattended items and reissued guidance pertaining facility inspections and active shooter incidents.”

She said Amtrak, in partnership with local, state and federal law enforcement, is ensuring that “robust security measures are in place at stations, on trains and along the tracks.”

In Maryland, Paul Shepard, a spokesman with the Maryland Transit Administration, said the agency is boosting security on MARC and commuter bus systems that carry thousands of riders to Washington each day, as well as the Baltimore transit network.

“There is an increased presence on our MARC and our regular core services here at the MTA,” Shepard said Monday afternoon. “We have not been able to verify that threat, but just based on what happened in Paris alone we are taking additional steps and raising the number of patrols….”

He and other officials reminded the public to remain vigilant and report suspicious activity.

“We can’t say it enough. If there’s something that doesn’t look right, please say something to somebody,” he said.

Some commuters said they welcome the increased security.

“I’m thankful for it and just hope they are safe and I am as well in the coming weeks,” said Michael Sackie, a regular Metro rider who was stuck in a traffic nightmare Monday morning, caused when a woman with a gun barricaded herself in a downtown office building.

[Streets in downtown D.C. reopen after barricade situation]

Extra precautions can give commuters a better sense of security in times like this, he said.

“I love my country and the people in it. I sure as heck don’t want nobody to get hurt,” he said.

The Metropolitan Washington Airports Authority, which oversees Reagan National and Dulles International airports said the agency is working with federal authorities to take steps necessary to keep its facilities and travelers safe following the events in Paris.

“As a rule we don’t discuss security procedures,” spokesman Christopher Paolino said via e-mail. “I can tell you that we are in touch with our airline and federal partners and are taking appropriate steps as necessary.”

A spokesman for Baltimore Washington International Airport said passengers will continue to see many security measures.  “And there are other security procedures and protocols that customers would not recognize,” he said. “As always, we ask the public to remain vigilant and aware of their surroundings, and to report any suspicious activity to law enforcement or security authorities.”

On Saturday, New  York Gov. Andrew M. Cuomo (D) announced stepped up security in that state’s transportation infrastructure, including the New York subway system, where riders can expect more random bag checks and more officers with heavy weapons.

Cuomo directed the Metropolitan Transportation Authority and the Port Authority of New York and New Jersey to be on a heightened state of alert.

“The safety of New Yorkers and our state’s visitors is our number one priority, and we are remaining vigilant and in close contact with local and federal officials and our partner law enforcement agencies,” Cuomo said in a statement Saturday.

Under the orders, the Port Authority Police boosted security of the agency’s bridge, tunnel, rail, World Trade Center and other facilities. The measures include increased patrols and checks of bags, buses, trucks and trains.

The MTA added uniformed and plainclothes patrols at Penn Station and Grand Central Terminal as well as other major stations in the network.

The San Francisco Bay Area Rapid Transit also is being extra vigilant.

“There have been no specific, credible domestic threat to the U.S. and there has been no change to the national terrorism alert level. However, BART Police Department has implemented higher visibility staffing,” said spokeswoman Alicia Trost.

Officials in Washington said they have put measures in place “that are not visible to the traveling public.”

Metro spokesman Dan Stessel said the steps were taken in “an abundance of caution following Paris.”

While the agency does not release details about its deployment strategies, Stessel said shifts have been extended — meaning more officers will be on duty at various times of day — and a combination of uniformed and plainclothes officers will be charged with patroling the system.

Metro customers can report suspicious activity or unattended items by calling Metro Transit Police at 202-962-2121 or texting “MyMTPD.”