From Aviation Herald it seems to be number's 3 and 4 engines.
By Simon Hradecky, created Sunday, Mar 9th 2014 20:19Z, last updated Sunday, Mar 9th 2014 20:19Z
A Cathay Pacific Boeing 747-400, registration B-HUF performing flight CX-748 from Johannesburg (South Africa) to Hong Kong (China), was departing Johannesburg's runway 03L when the aircraft flew through a flock of birds and ingested a number of birds into engines #3 and #4 (RB211, both right hand engines). The crew shut the engine #3 (inboard) down due to abnormal indications but kept #4 operating with normal indications. The aircraft stopped the climb at FL150, dumped fuel and returned to Johannesburg for a safe landing on runway 03R about one hour after departure.
A post flight inspection established birds had been ingested into both right hand engines causing damage to both.