A car bomb exploded Saturday near Madrid's track and field arena following a warning call by the armed Basque group ETA, officials said. No injuries were reported. The bomb went off at about 7 p.m. (1700 GMT) at a parking lot outside the Peineta complex, which is one of the sites that is part of the city's bid to host the 2012 Olympics, an Interior Ministry spokesman said, according to AP. The parking lot was nearly empty at the time and there was very little damage, he said on customary condition of anonymity. Police cordoned off the area. The blast came after a warning call made in ETA's name to the Basque daily newspaper Gara, the official said. ETA, which is blamed for killing more than 800 people since launching its fight for Basque independence in 1968, frequently makes warning calls to Gara. ETA is accused of targeting other Olympic-bid sites. --More 2236 Local Time 1936 GMT