A former pro-Jakarta militia leader on Thursday began serving a 10-year jail sentence in connection with the 1999 violence in East Timor as the United Nations Security Council prepared to discuss on Friday extending the mandate of a UN mission to the world’s newest nation.

Eurico Guterres, former head of the Aitarak, or “Thorn”, militia, is the first Indonesian to be sent to prison over the deaths of some 1,500 people. Of the 18 people tried by a special Jakarta court, he is the only one to have had his conviction upheld on appeal.