The shocking mass shooting in Orlando, Florida, has had the nation's police going on high alert everywhere, especially around LGBT events. The attack at a popular gay dance club is being called the worst mass shooting in U.S. history, with 50 people dead and 53 more injured.

On Sunday, police arrested an Indiana man who wanted to cause harm at the Los Angeles gay pride event in West Hollywood. This and the Orlando massacre have pushed other big U.S. cities to high alert, with stepped-up patrolling in gay neighborhoods and events.

In New York, more than 500 anti-terrorism officers were deployed immediately after the deadly massacre as a precautionary measure. Mayor Bill de Blasio said the city will witness more officers on patrol and overall beefed-up security at subway and Amtrak stations, all of the city's heavy-traffic areas and all the key New York City institutions.

Even without credible threats, authorities are taking no chances. The NYPD along with other federal law enforcement agencies has also said it is "closely monitoring" the unfolding of the subsequent events and investigation to get a better grasp of developments.

They are also working closely with the law enforcement authorities in Florida and the FBI to prevent future incidents like this. The NYPD along with the New Jersey Homeland Security officials are working hard to secure locations in Manhattan and the outer boroughs, all the major cities in the state of New York and at the Jersey Shore. The state is home to a large number of gay clubs and hosts many LGBT events round the year, so it is easy to understand such caution.

In Chicago, there are reports of increased patrols in the city's Boystown area, which is one of the nation’s largest and oldest LGBT enclaves along with other areas on the city's North Side. The Chicago PD has also beefed up security in all the heavily traveled areas, in downtown and the city's public transportation hubs.

The San Francisco Police Department said it is paying special attention to the Castro District, which is a major LGBT neighborhood, along with other LGBT venues. With the city all set to hold one of the nation's largest LGBT Pride celebrations June 25 and 26, all law enforcement agencies are on extra security duty. The San Francisco PD is also increasing police presence in high traffic and entertainment areas as well as mosques in the city.

There was also strict security for Sunday's Capital Pride Festival in Washington, D.C., which thankfully went off without hassle. Reports of increased patrols in prime locations are coming in from international locations like London as well, as the Metropolitan Police of London increases patrols around the LGBT community in the coming days.