LAGOS, Dec. 21 (Xinhua) -- Investigation is being urged into the killing of Nigeria's former defense chief Alex Badeh, who was ambushed and shot dead by unknown gunmen Tuesday near the nation's capital Abuja.

Badeh, former Chief of Defense Staff and Air Chief Marshal, died from gunshot wounds after gunmen attacked his vehicle on Abuja-Keffi expressway in central Nigeria when he was returning from his farm.

Badeh's death came a few months after a former chief of army administration, retired Major General Idris Alkali, was ambushed and killed in central north Plateau state.

In a statement, Nigeria's main opposition People's Democratic Party (PDP) expressed shock over the murder of Badeh, describing it as a national loss.

The ambush and killing of a military officer of Badeh's status has heightened fears and apprehensions on the level of insecurity in the country, particularly, the safety of average citizen, the PDP said.

The party called for an immediate investigation into the gruesome murder of Badeh.

Ibrahim Magu, chairman of the Economic and Financial Crimes Commission (EFCC), also issued a statement commiserating with the family of the former defense chief.

He described the development as "crude and senseless manner of the attack leading to the death of the former air chief."

He called on the relevant security agencies to ensure that the perpetrators were brought to book.

In its reaction, the Nigerian House of Representatives also called on the police and intelligence agencies to fish out the killers of Badeh.

The lawmakers, who condemned the act, also charged the Inspector General of Police Ibrahim Idris and the Director General of secret police Yusuf Bichi to bring the perpetrators to justice.

On its part, the Nigerian Air Force (NAF) has called on those spreading misinformation about the unfortunate incident to stop.

The Air Force spokesman Ibikunle Daramola said spreading erroneous reports and comments on the incident could have adverse effects on ongoing operations.

He said in a statement reaching Xinhua that substantial progress had already been made in the investigation and details would be communicated at the appropriate time. He added that the NAF is working closely with other relevant security agencies to determine the circumstances surrounding the death of the former defense chief.