Police are at the training ground off East Belfast GAA after reports that multiple explosives have been planted.
A PSNI spokesman said: "Police received an anonymous call on the evening of Wednesday, August 5, stating that a number of explosive devices had been left at playing fields at Church Road in Castlereagh.
"Officers attended and closed the site and are maintaining a cordon at the scene until a full search of the site can be carried out. There are no further details at present."
The club is only in its infancy and played its first matches last month.
Traditionally, East Belfast has been a staunchly Unionist area in a city historically divided along sectarian lines.
There has not been a GAA club in the area since St Colmcille's GAC closed in the 1970s. But earlier this year, the club was launched by a group of people, including former London footballer Downman David McGreevy.
Malone RFC offered its grounds to East Belfast GAA on a temporary basis. Irish language activist Linda Ervine was appointed as the club's first president.
The club has also released the following statement via Twitter: "The club wishes to advise members of an incident that occurred during training last night. It is the club’s understanding that, during the course of training, the police received a call that a package had been left somewhere in the vicinity of the playing fields upon which our members were training.
"On the advice of the PSNI, once a live situation was identified, the police and the club worked quickly to make people safe and help them disperse from the area calmly and efficiently. The club expresses its thanks to both the PSNI and to our playing members, who behaved impeccably during the situation. The creation and maintenance of a safe environment for sport to be played by all and the safety of our members whilst playing remains a priority for us all."
It adds: "The club intends to continue to work with the police, the community in East Belfast, and the public at large, whose support we have enjoyed on a daily basis, to ensure the continued safety and enjoyment of our members and patrons. Our door remains open, to all. The matter has now been passed to the PSNI."
The playing fields at Henry Jones' Playing Fields in the Castlereagh Hills are owned and operated by Belfast City Council.
East Belfast GAA formed earlier this year and as stated on their site: "We welcome people of all ages, genders and backgrounds"
In a statement, Alliance councillor Eric Hanvey said: "The people behind this alert are an absolute disgrace and do not represent East Belfast. East Belfast GAA has received plaudits from right across the community, and rightly so, in their attempt to help build a better future in East Belfast by bringing people together via sport, so they can live, work and play together in peace.
“Those behind security alerts such as these are clearly not interested in something so positive but rather only division and destruction. They are unwanted in East Belfast or anywhere else, and I urge anyone with information on them to contact police with it immediately.”
The club made its debut in the Down All-County Football League last month.