The European Space Agency (ESA) has confirmed that its Mars lander Schiaparelli has not been found, despite extensive searches by orbiting spacecraft.

The lander was due to touch down on the surface of Mars on Wednesday but lost contact with Earth just minutes before its scheduled landing.

ESA said in a statement on Friday that it was still not clear what had happened to the lander, but that the search would continue.

"The search for Schiaparelli is ongoing," the statement said. "The Mars Express and MAVEN spacecraft are both conducting targeted observations of the landing area, and the ExoMars Trace Gas Orbiter is also planning to carry out observations in the coming days."

The Mars Express spacecraft, which is in orbit around Mars, has already taken a number of images of the landing area but they have not shown any sign of the lander. The MAVEN spacecraft, which is also in orbit around Mars, is due to take further images in the coming days.

ESA said that it was also working with NASA to try to find the lander. NASA's Mars Reconnaissance Orbiter (MRO) spacecraft is due to carry out a high-resolution search of the landing area in the coming weeks.

The Schiaparelli lander was part of the ExoMars mission, which is a joint project between ESA and the Russian space agency Roscosmos. The mission is designed to study the atmosphere of Mars and to search for signs of life on the planet.

The lander was named after Giovanni Schiaparelli, an Italian astronomer who made a number of important observations of Mars in the 19th century.