Lebanon is observing a day of mourning a day after a police captain and at least three other people were killed in a bomb blast in eastern Beirut.

Security forces were to hold a memorial for Captain Wissam Eid, the target of the attack, and his body guard at a police station just outside of Beirut on Saturday.

The men's bodies were to be taken to the northern city of Tripoli after the ceremony, and then on to their respective villages to be buried.

Two passer-bys were also killed and nearly 40 people wounded in Friday's bombing, an attack likely to further polarize an already divided country.

The blast erupted in a mainly Christian area of the Hazmieh district, which houses several foreign embassies and homes of diplomats.

Lebanese security services have only recently come under attack in the series of political bombing plaguing the country.

Rula Amin, Al Jazeera's correspondent in Beirut, said Eid was an officer in the internal security forces who specialized in intelligence.

"The [explosion] is less than five minutes from Baabda, where Francois al-Hajj, another high-ranking security officer, was killed just over a month ago," she said.

New threat

Brigadier General Ashraf Rifi, commander of the Internal Security Forces, said that the security forces in Lebanon were facing a new threat.

"It was obvious that a terrorist message was sent to the Lebanese army when brigadier general Francois El-Hajj was martyred," he said.

"The second message was sent to the Internal Security Forces. Those apparatuses that are protecting the country are definitely being targeted."

Rifi said Eid was "definitely working on several extremely important cases."

"He had a role in all the investigations pertaining to the terrorist bombings [of the last three years]," he said.

Amin said that the latest bombing would be of further concern to the Lebanese.

"People have their hopes pinned on the security establishment to keep the political deadlock contained ...  now that the security establishment is being targeted, people feel very vulnerable and fragile," she said.

"The Lebanese have lost hope that these attacks will bring the feuding politicans together."

Dangerous precedent

Lebanon has suffered at least 30 bombings in the last three years, many hitting anti-Syrian politicians and journalists.

Elias Hanna, a military analyst and former general in the Lebanese army, said the dynamics of the attacks were changing.

"Now we are maybe seeing different targets [and] different objectives ... two weeks ago an American car was targeted by another explosion.

"Lebanon is now open – it is a theatre where everybody can settle accounts with others.

"This is a very dangerous transitional period for Lebanon since we don't have a new president," he said.

The explosion comes amid continuing discord between the majority political bloc and the opposition.

The ruling March 14 coalition has failed to reach an agreement with the Hezbollah-led opposition, which is supported by Syria, on a consensus president to replace Emile Lahoud, who stepped down in November.

"This bombing is proof that the [Syrian] mukhabarat [intelligence] have infiltrated Lebanese security services," a senior official from the March 14 coalition said, on condition of anonymity.

Syria condemned the bombing and blamed "Lebanon's enemies" for the explosion.

The explosion came 10 days after a car bomb damaged a US diplomatic car in the Lebanese capital, killing three people and wounding 16.

PHOTO CAPTION

Scene of the blast in eastern Beirut