<p id="thickbox_headline">An explosion destroyed part of a five-storey residential building in Russia's Naberezhnye Chelny city, some 930 km (580 miles) east of Moscow, the emergency service said on Monday.</p>.<p>Several people could be under debris, <em>Interfax</em> news agency reported, citing an unnamed source. Interfax and TASS state news agency also said a gas leak could be behind the explosion, citing anonymous sources. </p>
<p id="thickbox_headline">An explosion destroyed part of a five-storey residential building in Russia's Naberezhnye Chelny city, some 930 km (580 miles) east of Moscow, the emergency service said on Monday.</p>.<p>Several people could be under debris, <em>Interfax</em> news agency reported, citing an unnamed source. Interfax and TASS state news agency also said a gas leak could be behind the explosion, citing anonymous sources. </p>