BEIRUT, Lebanon (CNN) -- An explosion in Beirut has killed four people, including Lebanon's top anti-terror investigating officer, sources with the Lebanese Internal Security Forces and a government minister told CNN.

The attack in Hazmiyeh, a Christian neighborhood northeast of the capital, also wounded 13 others, security sources said.

"It was a powerful blast," CNN's Anthony Mills said. "I was less than half a mile away when it occurred and I felt the shock waves in the car I was traveling in.

"I arrived on the scene several minutes later and there was widespread damage -- several vehicles that had been reduced to hulks of burning, twisted metal ... debris scattered over a wide area."

The explosion killed Capt. Wissam Eid and his driver, the sources said.

Attacks of this nature have escalated as Lebanon has been in the midst of a political crisis as pro- and anti-Syrian lawmakers in parliament are locked in a battle to elect a president.

The nation has been without a president since November 23, when the pro-Syrian Emile Lahoud stepped down at the end of his term.

Last week, a car bomb struck a U.S. Embassy vehicle as it traveled along a coastal highway north of Beirut, killing at least three Lebanese civilian bystanders. The driver of the embassy vehicle sustained minor injuries, and the sole passenger walked away unscathed.

A week earlier, two U.N. peacekeepers were injured south of the capital after an explosion near their vehicle.

In early December, an explosion in Beirut's Christian suburb of Baabda killed Brig. Gen. Francois Al-Hajj, the head of operations for the Lebanese army, and his body guard.

In February 2005, the assassination of former Lebanese Prime Minister Rafik Hariri in Beirut sparked widespread protests that led to the ousting of Syrian forces from Lebanon.

U.N. investigators concluded in 2006 that Hariri's death may be linked to high-ranking Syrian officials. Syria has denied any involvement in the killings and said the U.N. tribunal investigating Hariri's death is a violation of its sovereignty.

In the past two years, four members of parliament have been assassinated.