SAN DIEGO (CBS 8) – Officials are investigating an alleged ISIS threat against a Southwest Airlines jet flying from San Diego to Dallas.

The threat was made on Twitter against Flight 4200, claiming there is a nuclear bomb on board. It's similar to several other false threats made against flights this weekend. In those cases, the planes were either evacuated on arrival or diverted to make a quicker landing.

Southwest Airlines released the following statement Monday:

"Any threat or alleged threat against the safety of our employees, customers or aircraft is a matter we take very seriously. We are working with the relevant authorities to ensure the safety of this and every flight. It is our policy not to further comment on matters of security."

The flight landed shortly after 6 p.m. and was not diverted.

The FBI is investigating the threat.