AMMAN (Reuters) - A bomb exploded near two cars carrying Israeli diplomats in Jordan on Thursday but none were hurt, their embassy said.

The blast occurred at around 5 p.m. (1500 GMT) on the approach to the Allenby Bridge crossing over the Jordan river to the Israeli-occupied West Bank. Israeli television said the incident took place 20 km (12 miles) from Allenby while Jordanian security officials said it was on the outskirts of the capital Amman.

Jordan’s close U.S. ties and 1994 peace accord with Israel are unpopular in the kingdom and there is strong support for Islamist militants in some areas.

In Amman, a Jordanian security source confirmed to Reuters that an explosive device had blown up near an Israeli car in the area, which had been cordoned off for searches.

Later Jordan’s Information Minister Nabil al-Sharif told the state news agency an explosive device placed on a pavement of a the main road leading to the Jordan Valley detonated just as several civilian cars and two Israeli embassy vehicles drove by.

Israeli embassy spokeswoman Merav Horsandi said Jordan told the Foreign Ministry it had opened an investigation into the incident.

Jordan is one of a handful of Arab countries to have diplomatic relations with the Jewish state. Those ties were frayed by Israel’s crackdown in 2000 on a Palestinian uprising that erupted in the West Bank and Gaza Strip.

Channel Two said the two cars had been en route from the Israeli embassy in Amman but that the ambassador, Danny Nevo, was not in either vehicle.

The occupants were “diplomatic staff and bodyguards,” Channel Two said, adding that the convoy had continued over Allenby and that at least one of the cars was lightly damaged.

Known to Jordanians as King Hussein Bridge, Allenby lies about midway on the 80 km (50 mile) route between Amman and Jerusalem, a few kilometers (miles) north of the Dead Sea.

Anti-Israeli feeling has risen in recent years and many politicians from independent figures to the Islamist led opposition have repeatedly demanded the severing of relations with Israel over its treatment of Palestinians.

The incident is the first attack on an Israeli target in Jordan in several years.

Security around the embassy and house of the Israeli ambassador has been beefed up, witnesses said.

Jordan has suffered from occasional political violence in recent years, including the assassination of a U.S. diplomat in 2002 and a hotel bombings in 2005 that killed dozens of people.

The bloodiest attack against Israelis in Jordan occurred in March 1997, when a Jordanian soldier killed seven Israeli schoolgirls at the border.

Most of Jordan’s 6 million citizens identify as Palestinians. Among them are 2 million listed by the United Nations as refugees, or the offspring of refugees, from the 1948 war of Israel’s creation.