A United Airlines flight bound from San Francisco to Mexico City made an emergency landing in Los Angeles on Friday after an apparent hydraulics issue, marking the fourth emergency involving a United flight in the span of a week, according to reports.

The Airbus A320 landed safely at Los Angeles International Airport around 4:30 p.m., with no reported injuries to the 110 people aboard, the Associated Press reported, citing a statement from United.

The craft has three hydraulics systems for redundancy purposes, the airline said. Preliminary information indicated that only one experienced an issue.

The Federal Aviation Administration is investigating the incident.

The emergency landing in Los Angeles came hours after another United flight rolled off a runway in Houston, the airline said. The 166 total passengers and crew aboard that flight were evacuated, with no injuries reported.

On Thursday, another United flight out of San Francisco - this one bound for Japan - made an emergency landing in Los Angeles after losing a tire during takeoff. 

Video footage showed the tire landing in an employee parking lot at San Francisco International Airport, where it slammed into a car and through a fence before coming to a rest. No injuries were reported.

And Monday, a United flight from Houston to Fort Myers, Texas turned around after one of its engines burst into flames, in a harrowing scene caught on video by several passengers. No injuries were reported.