Niall Horan has urged fans to "start looking out for each other" at his concerts, warning them that he will stop playing if they do not allay his crowd safety fears. 

The One Direction star-turned-solo-artist was in Mexico City at the weekend for two concerts and halted his performance on Friday night because of pushing in the crowd and some fans apparently fainting.

"Everyone needs to look after each other, or we're going to have to cancel the show," Horan told the audience at the Pepsi Centre. "Everyone look out for each other, ok?"

The Mullingar man also took to Twitter to get his safety message across.

"Guys you gotta start looking out for each other at shows," he wrote. "That's two shows in a week we've nearly had to cancel."

"I'm as excited to be there as you but ya gotta take care of yourselves in the audience," Horan continued. 

He then tried to lighten the mood by adding: "I mean have ya heard my album Hahahahah, it's not meant to look like a rave out there."  

Horan's world tour in support of his debut album Flicker now takes him to the US, where he will be performing shows until late September.

In June, Horan said he is planning to take a step back once his tour ends as he wants to focus on writing songs for his second album.

He recently premiered the new track Finally Free from the upcoming animated adventure Smallfoot. It opens in cinemas on Friday October 12.