An earthquake measuring 4.1 on the Richter scale shook El Hierro island last night.
This was the strongest of hundreds of tremblors recorded in recent days in the territory which suffered an undersea volcanic eruption in 2011, according to Spain's National Geographical Institute.
The earthquake struck at 3.41pm and its epicentre was in the Atlantic Ocean about 12 kilometres west of the island, a spokesman for the institute said. It was measured at a depth of 16 kilometres and was preceded by another earthquake measuring 4.0 on the Richter scale.
Since March 18 about 800 earthquakes have been recorded in El Hierro, which has about 10,000 inhabitants, the spokesman added.
Most have measured above 2.0 on the Richter but only a few have been strong enough for people on the island to really notice.
In October 2011 an underwater volcano erupted off the coast of El Hierro, and then two days later an earthquake measuring 4.3 on the Richter scale shook the island
.El Hierro, which means "Iron" in Spanish, has suffered thousands of earthquakes throughout much of 2011, but only a few of them were considered serious enough by officials to briefly close a tunnel linking the island's two main towns, Frontera and Valverde, and evacuate dozens of people.
The Canary Islands are located off the north-western coast of Africa. El Hierro, which has an area of just 267 square kilometres (103 square miles) is the most western of the seven islands of volcanic origin that make up the archipelago.
The last major volcanic eruption near the Canary Islands happened off Teneguia, Las Palmas, in 1971.