Moscow, 16 September 1999 (RFE/RL) - An explosion shattered an apartment building in a southern Russian city early today, killing at least 11 people. The blast brought down part of the nine-story building in the city of Volgodonsk, some 1,200 kilometers south of Moscow. More than 160 people were injured, over 40 of them seriously. At least five people were missing and believed trapped in the wreckage. The Interior Ministry said the blast was apparently caused by a bomb hidden in a truck outside the building. The explosion in Volgodonsk comes after a series of suspected terrorist attacks in Russia during the past two weeks. The attacks -- in Moscow and in the southern Russian republic of Dagestan -- have killed more than 270 people. Russian authorities have blamed the earlier attacks on Islamic militants fighting Russian control in the North Caucasus. Prime Minister Vladimir Putin has ordered an investigation into the Volgodonsk blast. Putin is expected to meet later in the day with President Boris Yeltsin to discuss the security situation in the country.