South Wales Police say they are responding to a "serious incident" which took place in Treorchy at midday on Friday.
No further details about the incident have emerged as yet, but it is said to involve "a number of casualties".
"The street has been closed off and people are advised to avoid the area until further notice. Updates will be released when they are available", SWP said on Twitter.
The officers asked the public to "refrain from posting speculation about the incident".
"We will release further information when appropriate to do - your support is appreciated", the police added.
SWP are also seeking witnesses but the nature of the incident has not been disclosed.
'What Happened?'
The Sun newspaper has described the incident in the village as a "stabbing attack" citing police accounts, but SWP has not officially confirmed this.
The paper claims that one man is feared dead and a number of others seriously injured after a stabbing attack in a local Blue Sky Chinese takeaway.
Labour MP for Rhondda Chris Bryant described the situation as "disturbing events" but also did not give any further details into the incident.
Residents say they have seen police cars, first responders and ambulances, including an air ambulance, milling about the area, but were not told what was going on.
Some locals have reportedly described the scene of the incident as a "bloodbath".
The Welsh Ambulance Service say they have attended the scene of the incident with "one rapid response vehicle, three emergency ambulances, our hazardous area response team and the Wales Air Ambulance" after being called to the area at 12:00 GMT.
Users on social media were trying to serach for answers of what could have happened at the scene as police still did not give any further details into the incident.