In Malaysia, a total of 19 hotspots were detected. There were 7 hotspots in Johor, 4 each in Kelantan and Pahang, 2 in Perak, and 1 each in Selangor and Sabah. The hotspots decreased slightly a day later. 167 hotspots were detected in Riau, out of a total of 252 in Sumatra. However, the number of hotspots in Riau climbed to 183 on 23 July, the highest number of hotspots detected in Riau since the haze returned. On 24 July, satellites detected 185 hotspots in Riau. Indonesian authorities said that the number of hotspots is expected to rise in August, when slashing-and-burning activity is very likely to peak, thus causing the haze to possibly thicken and increase. On 25 July, the number of hotspots in Riau decreased to 56, after 4 helicopters and 100 military personnel helped to fight the fires. There was a sharp increase in the hotspots in Indonesia on 26 August 2013, with 488 hotspots detected. There were 308 hotspots the day after, on 27 August 2013. On 23 June, the Asean Specialised Meteorological Centre (ASMC) in Singapore detected 642 hotspots, which were scattered mostly in parts of central and west Borneo that caused a haze in Brunei and other parts of Borneo. On 20 June, Brunei-Muara District recorded a "good" PSI reading of 44, Belait recorded a "moderate" 75, Temburong recorded a "moderate" 64, and Tutong recorded a "moderate" 66. By 21 June, The Department of Environment, Parks and Recreation of Brunei said the PSI readings were "relatively higher than normal", but air pollution levels were still considered "moderate" as the PSI readings in Brunei were still below 100. Belait recorded the highest PSI reading (98), followed by Temburong (94), Tutong (92), and Brunei-Muara (65), which was the lowest. On 24 June, haze in Brunei remained unchanged with PSI readings in Brunei-Muara at a good 43, Belait at a moderate 75, Temburong at a moderate 72 and Tutong at a moderate 73. On 26 June, the haze was gone from Brunei and PSI levels returned to "good" levels. However, "moderate" levels were still recorded on Tutong (70) and Belait (64).