A roadside bomb exploded near a convoy of vehicles carrying Israeli diplomats in Jordan on Thursday, but no one was injured, according to Israeli and Jordanian officials.

"All I can say at this moment is there was an attack that targeted an Israeli embassy vehicle," foreign-ministry spokesman Yigal Palmor said. "The Israeli embassy staff in the vehicle were not injured. The vehicle proceeded."

A senior Israeli official said Israel's ambassador to Jordan, Danny Nevo, wasn't in the convoy, but refused to specify who was.

The attack occurred shortly after 5 p.m. near the Jordanian village of Naour as the convoy was traveling from Amman, the Jordanian capital, to the Allenby Bridge border crossing into Israel, about 30 miles west of the capital, according to a Jordanian security official in Amman.

"We have launched a comprehensive investigation into the incident," the official said.

Israeli diplomats stationed in Jordan frequently return home to Israel at the start of the Jordanian weekend Thursday evening. Israeli television reported the two-car convoy was lightly damaged by the blast, but continued to a nearby Jordanian military base before being escorted by Jordanian security forces to the border.

An Israeli security official said that based on preliminary reports, it appeared the attackers had good intelligence. "They knew when the diplomats were traveling and where they were going," he said. "But it seems the explosives weren't used very professionally, and this is probably the reason there wasn't more damage."

This is the second breach of security in recent weeks for Jordan, which prides itself on its effective intelligence and security services. The suicide bomber who killed C.I.A. officers in Afghanistan last month was a Jordanian intelligence agent.

There have been numerous threats against Israeli diplomats and visitors to Jordan since the two countries signed a peace treaty in 1994. Last year, three alleged Hamas militants were sentenced to five years in prison for carrying out surveillance operations of the Israeli embassy in Amman. Also last year, two Jordanians were arrested for plotting the murder of an Israeli businessman in Jordan.

—Mohammed Najib contributed to this article.