The sources said the DFAs Office of Intelligence and Security (OIS) learned two weeks ago that "Arab-looking people" tried to hire last May 26 a Filipino worker in Abu Dhabi to drive a car loaded with explosives to the Philippine Embassy but the Filipino refused.
Another 40-year-old Filipino was similarly offered cash by Arab-looking people on the same week to carry an attaché case loaded with explosives into the US embassy there.
When the Filipino refused, the Arab-looking people threatened him and told him they knew where his wife, a nurse in Dubai, works.
"The Arab-looking men told the Filipino that they know where his wife works. After he was threatened, he decided to report the matter to the embassy," the source said.
After the embassy informed Abu Dhabi police and the US embassy, the worker was interrogated for 20 hours by UAE authorities, who were asked to protect him.
The foreign office is still working to verify the extent of the threat and "has not received any feedback" but security has been stepped up around the Philippine embassy and the Philippine Labor Center in Dubai.
OIS chief Eduardo Kapunan III flew to Abu Dhabi last Saturday to oversee security arrangements at Philippine facilities in the UAE.
In a report relayed to the foreign office, Philippine chargé daffaires Jose Ampeso said they received intelligence information about a bomb attack planned for Monday that did not succeed.
Local US embassy spokeswoman Karen Kelly declined to comment on the bomb threat against the American post in Abu Dhabi, saying they have not received information on the incident.