UNITED NATIONS — Top officials in America and Israel yesterday tied eruptions of violence in Lebanon and Gaza to larger regional developments and accused key regional players of fomenting the violence to serve their own interest.

In Washington, the White House press secretary, Tony Snow, pointed at Syria as a possible instigator of clashes between the Lebanese army and an Al Qaeda-affiliated group known as Fatah al-Islam. Specifically, he pointed to the timing of the violence: It erupted just as the U.N. Security Council was about to establish an international tribunal to try suspects in Lebanon’s political assassinations.

Yesterday, the Lebanese army struggled for the third day to end the Fatah al-Islam insurgency inside the Nahr al-Bared refugee camp just outside the northern city of Tripoli. At least 70 people are confirmed dead and the casualty numbers may climb; the number of casualties among fighters on both sides is about even, according to reports, and almost as many civilians have died.

The Syrian ambassador to the United Nations, Bashar Ja’afari, yesterday accused Israel of state terrorism while denying that his country was behind the latest violence in Lebanon. Syria, he told The New York Sun, is “at the forefront of fighting terrorism.”

Only a few of the fighters in the Nahr al-Bared camp are Palestinian Arabs, Mr. Ja’afari added. “They are not fighting on behalf of the Palestinian cause, which is just, as you know, and legitimate against the Israeli occupation,” he said.

The White House is studying whether Syria is behind the violence in the refugee camp, Mr. Snow said. But America “will not tolerate attempts by Syria, terrorist groups, or any others to delay or derail Lebanon’s efforts to solidify its sovereignty or to seek justice” in the case of an assassinated a former Lebanese prime minister, Rafik Hariri — “or, for that matter, to take on the violence that continues to plague the country.” According to Mr. Snow, the Syrians have “said that they wish to play a constructive role. One constructive role is, make sure that you’re not part of the violence.”

In Jerusalem, a deputy defense minister, Ephraim Sneh, accused Iran of being behind the weeklong escalation of Kassam rocket attacks launched by Gaza terrorists on Sderot and other southern Israeli towns. Although Mr. Sneh did not make the connection explicit, the escalation coincided with the leadup to tomorrow’s expected International Atomic Energy Agency report on Iran’s refusal to suspend parts of its nuclear program.

“Iran is behind this,” Mr. Sneh told the Web site of Israel’s Maariv newspaper yesterday, one day after a woman was killed in Sderot, and as at least eight rockets fell in nearby towns as part of a Hamas-led attack. “Iran finances these organizations, it trains them in these fighting techniques, and it smuggles weapons through tunnels into Gaza.”

According to an Associated Press report, America has considered launching an official complaint against the IAEA director, Mohamed ElBaradei, who told a Spanish newspaper that the suspension of Iran’s uranium enrichment program has now been “superseded by events.” Instead, Mr. ElBaradai said, Iran must be prevented from reaching “industrial scale” enrichment, the report said. America and its allies fear that such comments could weaken their demands to toughen council-imposed sanctions against Tehran.

At the Security Council, the Russian ambassador to the United Nations, Vitaly Churkin, said yesterday that his country remains opposed to several provisions in a proposed resolution that America, along with France and Britain, circulated to council members last week. The pact would empower an international tribunal to try suspects in the 2005 killing of Hariri and other assassinations in Lebanon.

According to Mr. Churkin, the proposal’s sponsors have yet to address several “legal problems” Russia has with the draft. Nevertheless, he told the Sun, it is “too early ” to decide whether his country will veto the resolution if brought to a vote.

“Violence will not deter the Security Council from moving forward,” the American ambassador to the United Nations, Zalmay Khalilzad, said. “It will redouble our resolve to move forward in the coming days.” The trial of the assassination suspects is needed “to deter such actions in the future, not only in Lebanon but beyond Lebanon, so there is a lot at stake here.”

Mr. Khalilzad spoke after a periodic council discussion about terrorism and its financing, during which the Israeli ambassador to the United Nations, Dan Gillerman, asked to speak not only about the phenomenon in general, but specifically about recent terrorist attacks on Israel mounted from Gaza. In the past, the United Nations has not defined such attacks as terrorism.

“Criminal terrorism is launched from an area Israel evacuated almost two years ago. The Palestinians decided to turn this area not into a place where one can live, but into a place that is being used for killing,” Mr. Gillerman told the Sun.

[The Associated Press reported yesterday that Lebanon has asked America for $280 million in military assistance to help put down an uprising by Al Qaeda-inspired militants operating from a Palestinian Arab refugee camp, the State Department said yesterday. About $220 million would go to the Lebanese Armed Forces and another $60 million to security forces, spokesman Sean McCormack said. He added that America is weighing the request.]