NAOUR, Jordan -- A roadside bomb exploded Thursday near a convoy of Israeli diplomats traveling through Jordan on their way home for the weekend, but no one was hurt, officials in both countries said.

Ambassador Daniel Nevo was not in the convoy, Israeli officials in Jerusalem said. There was no immediate claim of responsibility.

It was the first time a roadside bomb was used in an attack in Jordan, where suicide bombings and shootings have targeted foreigners in recent years. The method is widespread in neighboring Iraq.

The sundown attack also exposed a security breach for Israeli diplomats, who are usually escorted by security personnel from both countries and use different routes and departure times during their occasional travels in Jordan.

The explosion ripped through the right side of a curvy road cutting through hilly villages on the western outskirts of the capital, Amman. The blast left a large hole about 3 feet deep and damaged a highway guardrail.

Jordanian forensic officers were inspecting the site of the attack, a security official said. The area is halfway from the King Hussein-Allenby Bridge at the border.

Israel and Jordan, which signed a peace treaty in 1994, maintain close security cooperation and cordial diplomatic ties.

But anti-Israeli sentiments have been running high as the Israel-Palestinian conflict drags on without a solution. A significant portion of Jordan's population is made up of Palestinians.

The U.S. Embassy in Amman issued a statement recommending that American citizens avoid the Dead Sea Highway from Amman to the Dead Sea until further notice.

Police were trying to determine the size and complexity of the bomb, which appears to have exploded remotely, the official said, insisting on anonymity because he is not allowed to release details during early stages of investigation.

Israeli media reported that one or two roadside bombs exploded as the Israeli convoy passed, but the timing of the remote-controlled detonation was off and the vehicles were not seriously damaged. The convoy later crossed the bridge to Israel, Israel TV said.

The section of road, which is less monitored than the area closer to the bridge, is used by tourists and other travelers visiting the Dead Sea.

After the explosion, the convoy entered a small Jordanian army post as soldiers searched the area, Israel's Channel 2 TV said.

Jordanian police sealed off the main road leading to the area, sending large numbers of firefighters, police and ambulances to the scene.

Information Minister Nabil Sharif said in a brief statement that an "explosive device went off on the side of the road leading to the Jordan Valley" as "some civilian vehicles were passing by, including two Israeli diplomatic cars."

He said there were no injuries, and authorities have launched an investigation.

Two Jordanian security officials said the attackers may have thought that the Israeli ambassador to Jordan was in the convoy.

In Amman, Israeli Embassy spokeswoman Merav Horsandi confirmed there was a blast next to a convoy carrying embassy employees. "All I can say now is that everyone is fine," she said.

In Jerusalem, Israeli officials said four passengers and two security guards were in the convoy and they were heading to Israel for the weekend.

There have been several attempted attacks on Israeli citizens in Jordan in past years.

In 2001, Israeli jeweler Yitzhak Shnir, 51, was gunned down in Amman. An unknown group claimed responsibility, saying Shnir was an Israeli spy.

In 2005, al-Qaida in Iraq said after its triple hotel blasts in Amman that one of the targets included a hotel known to be patronized by Israelis.