Media playback is not supported on this device
The Blues lead the top flight with 59 points with 14 games remaining.
Second-placed Tottenham lead the chasing pack with 50 points, and just five points separate them in second and Manchester United in sixth.
"I think there are six teams who are very strong and can fight to win the title," said Conte.
Third-placed Manchester City, Arsenal, in fourth, and fifth-placed Liverpool make up the top six.
"Manchester United? Yes. They have a great squad," added Conte.
"There are 14 games to play and five teams as well as us who can fight to win it. It's important we don't make mistakes in the race."
Chelsea face a trip to Burnley on Sunday for a 13:30 GMT kick-off. The Clarets have won their last seven games at home in all competitions with 28 of their 29 league points so far this season coming at Turf Moor.
"There are teams at the bottom who win and draw so you must have the right concentration," said Conte.
"If your ambition is to stay in the top four or top six, you can have highs and lows.
"If you want to win [the title] you must have concentration and focus and know that in every game you can lose points."

The 36-year-old defender, who took up a coaching role at St James Park last year, has not featured in City's first team since the end of February.
"Regarding the playing, I know in my head that things are slowly coming to an end," he told BBC Sport.
"I'm not knocking on (manager) Paul Tisdale's door asking why I'm not playing every week, that's for sure."
Butterfield has been at Exeter for three seasons, having spent eight years at Crystal Palace, where he famously scored a six-minute hat-trick against Wolves in the FA Cup in 2010.
"At the minute it is a little bit of an emergency style usage of myself," Butterfield added of his role within the Exeter playing squad.
"We've not openly discussed where we're going forward with that, I'm sure next season it'll be more coaching-based, with perhaps the registration still being held as a 'what if'.
"I'm enjoying what I'm doing with Tis (Tisdale) and the rest of the coaching staff and I'm certainly enjoying working with the lads on the coaching front and I hope they're enjoying working with me.
"I'm thankful to Tis for giving me the opportunity to use the transition into the coaching.
"It's a win-win for both as Tis uses me if and when and I'm alongside him every day in training and close to the boys trying to get the best out of them."
Chelsea manager Antonio Conte says it would be a "very big mistake" for his side to think they are close to winning the Premier League title.
[NEXT_CONCEPT]
Exeter City player-coach Danny Butterfield says his playing career is coming to an end.