BEIRUT - Hezbollah chief Hassan Nasrallah vowed on Thursday to avenge the killing of top commander Imad Mughniyeh who died in a Damascus car bombing last year which is widely blamed on Israel.

"The Israelis live in fear of our revenge," Nasrallah said in a rare news conference via video link. "The decision to respond to the killing is still on. We decide the time and place."

Nasrallah said it was clear Israel was behind Mughniyeh's killing in a car bomb blast last February.

"A probe by Syria indicates that (Israel's spy agency) Mossad was behind the assassination," he said.

In his wide-ranging news conference that touched on a number of subjects, Nasrallah said DNA tests on the remains of four fighters handed over by Israel in a 2008 prisoner swap failed to prove their identity.

"We sent DNA samples of the remains to a laboratory in France... a few days ago the results came out and they were not helpful," Nasrallah said.

"We cannot say that any of the four remains belong to (Palestinian) Dalal al-Moghrabi, (Lebanese) Yehya Skaf or the other two martyrs... so we consider these remains to belong to unknown martyrs."

"We do no consider that we have the remains of any of the martyrs who died in Dalal's operation," said Nasrallah.

Israel last year transferred to Lebanon the remains of 199 Palestinian and Hezbollah fighters, saying they included Moghrabi and Skaf.

Under the prisoner exchange, Israel freed five Lebanese prisoners, including Samir Kantar.

Hezbollah in return handed over the remains of two Israeli soldiers seized in 2006.

In his speech, delivered in honor of "Liberty Day," Nasrallah accused Israel of holding on to the remains of 350 Lebanese and Palestinian gunmen, instead of returning them to their families.

"We do not claim to have an exact number, but we know that about 350 Palestinian and Lebanese fatalities have yet to be returned to their families. We consider them to be missing in action and hold Israel responsible for their fate," he said.

Nasrallah said Hezbollah had proof that Israeli security forces snatched gunmen's bodies while operating in Lebanon. "We are in possession of photos that prove the forces of the occupation took the bodies and airlifted them (to Israel). The number of the missing gunmen is in the hundreds. Most of them are Lebanese, while the rest are Palestinian.

"Israel is responsible for their bodies because some of them were captured at Israeli checkpoints, while others were apprehended at their own homes and were never heard from again.

He added that "the issue of the 11,000 Palestinian prisoners held in Israel should fall under the responsibility of the Arab nation and should be treated as jihadi and moral matter."

Nasrallah also called on the Lebanese government to reveal the fate of the four Iranian diplomats who were kidnapped in Lebanon in 1982 by the Christian Lebanese Forces (LF) militia during the civil war. Israel claimed that they were killed by the LF, while Hezbollah believes they were handed over to Israel.

At the time, the Christian-dominated Lebanese Forces, were held responsible for kidnapping the diplomats. Nasrallah said the Lebanese Forces need to help establish the truth about the diplomats' fates.

The current head of the Lebanese Forces, Samir Geagea, has said the four were kidnapped in northern Lebanon and went missing since then. Geagea has denied he had any news about their current fate.

Obama same as Bush

When it comes to Israel, Nasrallah sais there is no difference between Barack Obama and George W. Bush, and that the new U.S. administration has so far shown full support for the Jewish state - Hezbollah's archenemy.

The remarks were the first comments by the reclusive Sheik Hassan Nasrallah since the Jan. 20 inauguration of the new U.S. president. Although a militant group, Hezbollah is today also a political force and a partner in the Lebanese government with veto power over all decisions.

"The conduct of the new administration when it comes to Israel is ... one of absolute support," Nasrallah said, speaking via videolink from his hiding place. "I have not sensed until now that there is any difference between the two (U.S.) administrations."

He also denounced Israel's 22-day offensive on the Gaza Strip, claiming Israel failed to achieve its target of routing out militant Palestinian Hamas from the coastal strip. Hezbollah is a Hamas ally, and both are supported by Iran and Syria.

Nasrallah went into hiding at the onset of the July 2006 Israel-Hezbollah and has rarely been seen since in public, fearing assassination. -With Agencies