By Siyabonga Sishi and Nellie Peyton STILFONTEIN, South Africa (Reuters) - South African rescuers were making final efforts on Thursday to ascertain whether anyone was left in an illegal gold mine deep underground where at least 78 people died during a police siege,

The clampdown on illegal mining cut off food and water to hundreds of miners underground. At least 78 bodies were pulled from a mining shaft this week, and more are believed to remain underground.

Illegal mining is common in parts of gold-rich South Africa. Typically, undocumented miners known as zama zamas - from an isiZulu expression for "taking a chance" - move into mines abandoned by commercial miners and seek to extract whatever is left. Some are under the control of violent criminal gangs.