Of the 16 ha, 13 ha were found in Dumai City, Head of the BPBD Riau Said Saqlul Amri said in an e-mail message here on Sunday.
The remaining three hectares were located in Rokan Hilir District, he said.
Two hotspots of the forest fires were put out recently, according to the Riau Forest and Land Fire Anticipation Task Force.
During February-April 2014, there were a total of 242 forest and land fires in the province, razing 21,925 hectares of forest and plantation areas.
In Bengkalis District alone, 8,221 hectares of forest and plantation areas were destroyed by fires during the two-month period. Meanwhile, in Meranti District, 7,215 hectares were gutted by fires.
Forest and land fires occurring in the Riau Province between February and April 2014 caused economic losses worth more than Rp20 trillion, as per data furnished by the National Disaster Mitigation Agency (BNPB).
"It should be kept in mind that once the fires break out, it will be difficult to extinguish them and can cause huge losses," BNPB spokesman Sutopo Purwo Nugroho stated recently.
The haze disaster triggered by the fires disrupted around 30 percent of the economic activities and caused monetary losses in Riau.
The BNPB had spent around Rp164 billion, or one-third of its budget, to deal with the fires nationally.
The haze affected the health of several residents in Riau and the neighboring provinces, such as in West and North Sumatra.
The largest loss caused by forest and land fires in Indonesia was in 1997, when fires wiped out millions of hectares of forest and plantation areas and caused losses worth US$2.45 billion.
The El Nino phenomenon is forecast to develop and affect Indonesia between May and October 2014. El Nino-induced drought usually triggers forest and peatland fires in Indonesia.