Ukraine on Wednesday hit a Russian oil refinery in Ryazan, south of Moscow, in a new drone attack on Russia's energy infrastructure, authorities said.

Ukraine has launched drones into Russia regularly since last year as the war between the two drags on, increasingly targeting sites such as factories and oil refineries deep inside Russia.

Clashes broke out on Wednesday at pro-Palestinian demonstrations on the campus of the University of California, Los Angeles, U.S. television media footage showed, as dozens of universities around the United States struggle to contain similar protests.

According to CNN, the clashes erupted just before dawn between rival pro-Palestinian and pro-Israeli groups.

Donald Trump was held in contempt of court Tuesday and fined $9,000 for repeatedly violating a gag order that barred him from making public statements about witnesses, jurors and some others connected to his New York hush money case. If he does it again, the judge warned, he could be jailed.

Prosecutors had alleged 10 violations, but New York Judge Juan M. Merchan found there were nine. The ruling was a stinging rebuke for the Republican former president, who had insisted he was exercising his free speech rights.

A Russian attack on the Ukrainian city of Kharkiv killed two people and wounded six on Tuesday, the regional governor said.

"According to preliminary information, two people were killed and six were wounded in the strikes on Kharkiv," governor Oleg Synyegubov said.

The United Nations' top court is ruling Tuesday on a request by Nicaragua for judges to order Germany to halt military aid to Israel, arguing that Berlin's support enables acts of genocide and breaches of international humanitarian law in Gaza.

Nicaragua's case is the latest legal bid by a country with historic ties to the Palestinian people to stop Israel's offensive. Late last year, South Africa accused Israel of genocide at the court. The cases come as Israel's allies face growing calls to stop supplying it with weapons, and as some including Germany have grown more critical of the war.

Dozens of protesters took over a building at Columbia University in New York early Tuesday, barricading the entrances and unfurling a Palestinian flag out of a window in the latest escalation of demonstrations against the Israel-Hamas war that have spread to college campuses nationwide.

Video footage showed protesters on Columbia's Manhattan campus locking arms in front of Hamilton Hall early Tuesday and carrying furniture and metal barricades to the building, one of several that was occupied during a 1968 civil rights and anti-Vietnam War protest on the campus. Posts on an Instagram page for protest organizers shortly after midnight urged people to protect the encampment and join them at Hamilton Hall.

French police removed dozens of students from the Sorbonne university after pro-Palestinian protesters occupied the main courtyard of the elite institution in Paris on Monday.

About 50 protesters set up tents at midday Monday at the Sorbonne university courtyard in support of Palestinians, echoing similar encampments and solidarity demonstrations across the United States.

Chinese President Xi Jinping will visit France, Serbia and Hungary next week as Beijing appears to seek a larger role in the conflict between Russia and Ukraine that has upended global political and economic security.

The visit by Xi, China's president and head of the ruling Communist Party, is his first to Europe in five years and will "inject new momentum to the peaceful development of the world," Foreign Ministry spokesperson Lin Jian said at a daily briefing on Monday.

Protests are roiling college campuses across the U.S. as upcoming graduation ceremonies are threatened by disruptive demonstrators, with students and others sparring over the war in Gaza and its mounting death toll.

Many campuses were largely quiet over the weekend as demonstrators stayed by tents erected as protest headquarters, although a few colleges saw forced removals and arrests. Many students are demanding their universities cut financial ties with Israel over the large-scale operation in Gaza it says was launched to stamp out the militant Palestinian group Hamas.

President Joe Biden is out to win votes by scoring some laughs at the expense of Donald Trump, unleashing mockery with the goal of getting under the former president's thin skin and reminding the country of his blunders.

Like a comic honing his routine, the Democratic president has been testing and expanding his jokes over the past few weeks. It started with jabs about his Republican opponent's financial problems, and now Biden regularly pokes fun at Trump's coiffed hair, his pampered upbringing and his attempt to make a few extra bucks by selling a special edition of the Bible.