BUDAPEST, Feb 15 (Reuters) - U.S. Secretary of State Marco Rubio on Sunday called "troubling" a report by five European allies blaming Russia for killing late Kremlin critic Alexei Navalny using toxin from poison dart frogs, adding that Washington had no reason to question it.

"We obviously are aware of the report. It's a troubling report. We're aware of that case of Mr. Navalny and certainly... we don't have any reason to question it," Rubio told reporters at a news conference in Brastislava during a visit to Slovakia.

By Nidal al-Mughrabi and Steven Scheer

CAIRO/JERUSALEM, Feb 15 (Reuters) - Israel fired airstrikes across the Gaza Strip on Sunday, killing at least 11 Palestinians, Palestinian officials said, in what the military called a response to ceasefire violations by Palestinian militant group Hamas.

Gaza medics said an Israeli airstrike on a tent encampment housing displaced families killed at least four people, while health officials said another strike killed five in Khan Younis in the south and another person was shot dead in the north.

The start of this year's Berlin Film Festival was marked by a row over how far film should venture into politics but for prominent French-Palestinian actor Hiam Abbass, "everything we do is a political act".

Abbass is starring in two films being presented at this year's Berlinale festival and in an AFP interview she emphasised the importance of a politically engaged approach to cinema.

Feb 14 (Reuters) - President Donald Trump and Israeli Prime Minister Benjamin Netanyahu agreed at a White House meeting on Wednesday that the U.S. would work to reduce Iran's oil exports to China, Axios reported, citing two U.S. officials briefed on the issue.

"We agreed that we will go full force with maximum pressure against Iran, for example, regarding Iranian oil sales to China," Axios reported on Saturday, quoting a senior U.S. official.

Gaza's civil defence agency reported that Israeli strikes killed at least 12 people since dawn on Sunday, while a military official said the attacks were in response to ceasefire violations.

Despite a US-brokered truce that entered its second phase last month, violence has continued in the Palestinian territory, with Israel and Hamas blaming each other for violating the agreement.

The civil defence agency, which operates as a rescue force under Hamas authorities, said one strike hit a tent of displaced people in northern Gaza and another targeted an area in the south.

By Phil Stewart and Idrees Ali

WASHINGTON, Feb 14 (Reuters) - The U.S. military is preparing for the possibility of sustained, weeks-long operations against Iran if President Donald Trump orders an attack, two U.S. officials told Reuters, in what could become a far more serious conflict than previously seen between the countries.

The disclosure by the officials, who spoke on condition of anonymity due to the sensitive nature of the planning, raises the stakes for the diplomacy underway between the United States and Iran.

Cheered by a massive crowd under a sea of flags, the son of Iran's toppled monarch told a mass rally in Munich on Saturday he wants to lead the country into a democratic future.

Police said some 250,000 pro-monarchist opponents of the Islamic republic's leadership travelled from across Europe to take part in the demonstration held while world leaders met nearby at the Munich Security Conference.

Feb 14 (Reuters) - Israeli Foreign Minister Gideon Saar will attend U.S. President Donald Trump's first formal Board of Peace meeting on February 19, two Israeli officials said on Saturday.

U.S. officials told Reuters this week that Trump will announce a multi-billion dollar reconstruction plan for Gaza and detail plans for a U.N.-authorized stabilization force for the Palestinian enclave at the meeting in Washington.

TORONTO, Feb 14 (Reuters) - Canadian Foreign Affairs Minister Anita Anand said Canada wants a change of government in Iran but would not say whether it would support a U.S. military strike, the Globe and Mail reported on Saturday.

“We will not open diplomatic relationships with Iran unless there is a regime change. Period,” Anand told the Globe and Mail in an interview in Germany, where she is attending the Munich Security Conference.

Canada has particularly poor relations with Iran and cut off diplomatic ties in 2012.

By Humeyra Pamuk, Sabine Siebold and Muvija M

MUNICH, Feb 14 (Reuters) - Secretary of State Marco Rubio cast the United States as the "child of Europe" in a message of unity on Saturday, offering some reassurance as well as levelling more criticism at allies after a year of turmoil in transatlantic relations.

Rubio was addressing the annual Munich Security Conference, where Europe's leading powers have tried to project their own independence and strength while straining to keep a long-time alliance with the U.S. under President Donald Trump alive.