Hamas claims he was "assassinated".
(MEMO) A senior Hamas leader was killed in the Palestinian refugee camp Yarmouk in Syria, the group said on Monday.
"Hamas mourns martyr Yehia Hourani, who was assassinated Monday in Palestine Hospital in the Yarmouk refugee camp," Hamas said in a statement.
The statement said he was killed while carrying out his "humanitarian duty at the hospital".
Hourani was active in relief and humanitarian work, helping to train hundreds of paramedics and nurses, the statement added.
It is estimated that around 166 people have died in the camp as a result of the lack of food and medical care available since the Syrian regime besieged the camp in July 2013, the Friends of Humanity organization said last month.
Relations between Hamas and President Bashar al- Assad's regime deteriorated after the movement refused to support the regime against Syrian rebels following the outbreak of the Syrian revolution in March, 2011.