Mexico City, Aug 4 (EFE) A powerful earthquake measuring 6.9 on the Richter scale rattled northwestern Mexico Monday, but there was no report of any casualty, officials said.

The quake struck at 1:00 p.m. (1800 GMT) with its epicentre between the islands of Angel de la Guarda and Tiburon, Mexico's National Seismological Service chief Carlos Valdes said.

The quake was also felt in the states of Baja California and Sonora, the seismological service said, adding that several after shocks were also registered in the area.

'Authorities in Sonora said there was no damage either in the capital (Hermosillo) or on the coast,' national civil defense coordinator Laura Gurza said.

'In the state of Baja California there are very few towns,' Valdes pointed out, adding that the epicenter was between 200 and 250 km from Hermosillo and some 400 km from Tijuana and Ensenada near the US border.