Nicosia: Unidentified attackers killed a nuclear engineer on Wednesday in the Syrian city of Homs, 160 kilometres (100 miles) north of Damascus, the Syrian Observatory for Human Rights said.
"Nuclear engineer Aws Abdel Karim Khalil was killed this morning by unknown attackers," the Britain-based rights group said in a statement.
On Tuesday in the same city, unidentified attackers killed Mohamed Ali Aqil, deputy rector the architecture faculty at Al Baath University, and Nael Dakhil, director of the military petrochemical school.
Rights activists in the city accuse Syrian authorities of carrying out the killings. Rights activists, who set up an alliance under the name Al Ghad on September 18, accuse the authorities of having "killed scientific personalities in Homs, trying to repeat the scenario of assassinations" perpetrated in Syria in the 1980s.
Syria for some six months has been in the throes of a peoples' uprising in which the UN says some 2,700 people have been killed by an army crackdown.
The authorities in Damascus accuse the West and "armed gangs" of trying to sow chaos in the country.
On Monday, security forces killed nine civilians during a sweep against militants in the northwest, south and centre of the country, activists said.