An explosion tore apart a coalition tank in southern Afghanistan on Tuesday, killing one Romanian soldier and wounding four others, the military and a witness said.

The attack came amid a large U.S.-led offensive across four southern provinces aimed at curbing the deadliest spike in Taliban violence since the 2001 ouster of the extremist regime.

CountryWatch: Afghanistan

Tuesday morning's blast targeted a four-vehicle Romanian convoy just outside the southern city of Kandahar as the troops were returning to their base, the Romanian defense ministry said.

It said one vehicle drove over an explosive device, killing a 38-year-old corporal instantly and wounding three other soldiers, one seriously.

A fourth soldier suffered leg wounds when he stepped on another explosive device after the remaining Romanian vehicles stopped to help the targeted vehicle, the statement said. The wounded soldiers were airlifted by helicopter to a military medical facility in Kandahar, 260 miles southwest of the capital, Kabul.

The explosion was so powerful that it split a tank in two pieces and left its hull engulfed in flames, according to an Associated Press reporter at the scene.

It was not immediately clear what caused the fatal explosion, but military officials suspected a roadside bomb or land mine, Canadian spokeswoman Capt. Julie Roberge said.

At least three other Romanian troops have been killed in Afghanistan since 2003. Romania has about 700 peacekeeping troops in Afghanistan.

Attacks on coalition forces have continued despite the launch of a large offensive, dubbed Operation Mountain Thrust, aimed at capturing or killing Taliban militants. More than 10,000 coalition and Afghan troops have spread out over four southern provinces — Uruzgan, Helmand, Kandahar and Zabul.

Coalition helicopters bombed a Taliban camp in Helmand's mountainous Baghran district late Monday, killing five militants and wounding eight, said Haji Ghulam Muhiddin, the provincial governor's spokesman. The wounded militants were taken away by other Taliban fighters, he added.

In other violence, militants attacked a Turkish construction company in western Afghanistan's Farah province Monday, killing one Turkish driver and three Afghan guards, said provincial police chief Gen. Sayed Aqa Saqib. Two other Afghan guards were wounded.

Taliban militants also raided the Khoshalmand district offices in the southeastern Paktika province late Monday, starting a three-hour battle with security forces that left six insurgents dead, provincial Gov. Mohammed Akram Akhbalwak said. Fifteen other militants and one policeman were wounded.

Since Operation Mountain Thrust began in earnest last week, about 110 suspected militants have been killed. At least 10 coalition soldiers have died in combat since mid-May.

More than 600 people, mostly militants, have been killed in the past month as insurgents launched increasingly bold attacks, including suicide bombings and ambushes, against coalition forces.