BERLIN (AFP) - Germany on Wednesday (May 12) said Israel had a "right to self-defence" against deadly rocket fire by Palestinian militants, as Germany's Jewish community asked for stepped-up protection in light of the tensions.

Chancellor Angela Merkel's spokesman Steffen Seibert said her government "condemns these incessant rocket attacks from the Gaza Strip against Israeli cities in the strongest terms", saying they "could not be justified".

"Israel has the right to self-defence against these attacks," he added.

Mr Seibert noted that both Arab and Jewish Israeli citizens had been killed in the barrage of rockets in recent days by Hamas and "allied extremist groups".

"Their goal is to arbitrarily and indiscriminately kill people," he said.

Palestinian militants have launched more than 1,000 rockets since Monday, according to Israel's army, which has launched hundreds of air strikes on Hamas and other Islamist groups in the crowded costal enclave of Gaza.

The most intense hostilities in seven years were triggered by weekend unrest at Jerusalem's Al-Aqsa mosque compound, which is sacred to both Muslims and Jews.

They have killed at least 48 people in Gaza, including 14 children, two Palestinians in the West Bank, and five Israelis.

The spasm of violence prompted Germany's Jewish community to sound the alarm after Israeli flags were set alight in front of synagogues in two cities.

Mr Josef Schuster, president of Germany's Central Council of Jews, which represents about 200,000 Jews living in the country, said he feared Middle East tensions were spilling over.

"Israel and Jews as a whole are subjected to hatred and incitement, particularly on social media, he said, adding "the protection of Jewish institutions must be increased".

Anti-Semitic crimes have risen steadily in Germany in recent years, with 2,032 offences recorded in 2019, up 13 percent on the previous year, according to official figures.

The government's top official tasked with fighting anti-Semitism, Mr Felix Klein, told local media he found the flag-burning incidents "alarming" and called for "adequate" protection for Jewish sites in light of the heightened threat level.

A German court in December handed down a life sentence to the assailant behind a deadly far-right attack last year that nearly became the country's worst anti-Semitic atrocity since World War II.

After failing to storm a synagogue, the gunman shot dead a female passer-by and a man at a kebab shop.