Jakarta, Mar 14 (IANS): A powerful 6.9-magnitude earthquake jolted Indonesia's North Sumatra province on Monday, but there were no immediate reports of damage or casualty, officials said.

The quake triggered no tsunami, the Meteorology, Climatology and Geophysics Agency said.

The quake struck at 4.09 a.m., with the epicentre at 161 km southeast of Nias Selatan district and the depth at 25 km under the seabed, Xinhua news quoted the agency as saying.

A 6.0 magnitude aftershock followed the main quake at 4.38 a.m., it said.

The jolts were also felt in nearby provinces of West Sumatra and Jambi, according to the agency.

In North Sumatra province, the intensity of the quake was felt at IV MMI (Modified Mercalli Intensity) in Nias Selatan district and Gunungsitoli town, it added.

In West Sumatra province, the intensity was felt at IV MMI in the provincial capital of Padang, Siberut island, and III MMI in Padang Panjang town, Bukit Tinggi town, Pasaman Barat district, Pasaman district and Tua Pejat village in Mentawai Island district, the agency further said.

The jolts were only felt at II MMI in Jambi province's Kerinci district, it added.

Two senior officials of the local disaster agency and local search and rescue office confirmed that there were no immediate report of damage or casualty triggered by the tremors.

"The jolts were felt, but so far, there are no reports of buildings or houses destroyed or those injured. However, we still monitor the risks of the quake," Agus Wibisono, head of the Search and Rescue Office for Nias Island, where Nias Selatan and Gunungsitoli are situated, told Xinhua.

Similarly, the Head of the Operation Unit of the Disaster Management and Mitigation Agency of West Sumatra province, Jumaidi, told Xinhua that there was no immediate report of casualty or damage in the province triggered by the tremors.

"In Padang city, Siberut and others, there are no damages. However, we are still monitoring the situation," the official said.