SHEBAA, Lebanon, April 2 (IslamOnline & News Agencies) - Israeli occupation forces shelled southern Lebanon Tuesday, claiming that a Katyusha rocket landed in northern Israel overnight, news agencies reported.

Eight Israeli shells exploded near the Lebanese border village of Shebaa, accompanied by bursts of heavy machine-gun fire, but no casualties were reported, Agence France-Presse (AFP) reported.

Israeli security officials claimed that a single rocket had exploded near the northern Israeli town of Kiryat Shmona, again without causing any damage or casualties.

But a United Nations spokesman said he had no report of a Katyusha rocket being fired, the Israeli daily newspaper, Haaretz, reported.

”The Israelis can say what they want, but we have no confirmation or report on that incident yet,” said U.N. spokesman in southern Lebanon Timor Goksel, according to the paper.”We are still inquiring about it.”

He added that an escalation on the Israeli-Lebanese border would be "very serious".

Israel, however, pinned the blame of the claimed rocket on the Islamic resistance movement Hezbollah which forced Israel to end its 20-year occupation.

The firing was reported Tuesday, April 2, at the end of a news bulletin of Hezbollah's television channel Al-Manar, and was unclaimed.

Israeli officials said the group was stepping up its activities in support of the Palestinian uprising and warned its backers Lebanon and Syria.

Hezbollah chief Hassan Nasrallah said last month that the movement, which was instrumental in forcing Israel to end its 20-year occupation, would not stand by if the Palestinians were faced with "a war of extermination".

Lebanese Prime Minister Rafiq Hariri will travel to Washington to meet U.S. President George W. Bush April 17, Lebanese daily newspaper, As-Safir, reported Tuesday, according to AFP. 

Hariri's information office declined to confirm the information reported by As-Safir's Washington correspondent who said the talks will cover the "dangerous situation in the region."