Cairo - Mohamed Badie and several other prominent Islamists were sentenced to life in prison on Saturday for murder and inciting violence, judicial sources said, part of an ongoing crackdown on the outlawed group.

Badie has faced numerous trials and has accumulated two death sentences and five sentences to life in prison in separate cases, which still may be appealed. Saturday's sentencing related to an attack on a police station in the city of Port Said in 2013 in which five people were killed. The attack was part of a wave of violence that swept across Egypt after the army removed elected Islamist president Mohamed Mursi from power in July 2013 following mass protests against his rule.

Senior Brotherhood leader Mohamed El-Beltagy, Islamist cleric Safwat Hegazy, and 16 others were also sentenced to life in prison, 28 to ten years in prison and 68 acquitted. Another 76 people were given life sentences in absentia. Charges ranged from murder and inciting violence to stealing weapons and destruction of public and private property.

After hearing their sentences, the defendants defiantly flashed the four-finger Rabaa sign synonymous with the Brotherhood's 2013 sit-ins and chanted "down with military rule" from inside a cage in the courtroom. Since deposing Mursi, the authorities have held mass trials for thousands of Muslim Brotherhood supporters, with hundreds receiving death sentences or lengthy prison terms. Mursi was sentenced to death in June over a mass jail break in 2011.

This has drawn criticism from activists and rights groups at home and abroad. The Egyptian government says the judiciary is independent and that it never intervenes in its work. The government deems the Brotherhood a terrorist group. The Brotherhood, Egypt's oldest opposition movement dating back decades, says it remains committed to peaceful activism. President Abdel Fattah al-Sisi approved an anti-terrorism law this month that sets up special courts. Human rights groups say the law uses security threats as a pretext to curtail political freedoms won in a 2011 uprising.

Moreover, Four members of Hamas' armed wing were abducted in Egypt's Sinai Peninsula on Wednesday after the bus they were on was stopped by unidentified gunmen, sources close to the Palestinian group and Egyptian security officials said. Egypt accuses Hamas of supporting militant groups seeking to topple the Cairo government, an allegation the movement denies.

Hamas warned in a statement that the abductions could strain ties with Egypt, which faces a serious security challenge from Islamist militants.

"The graveness of such an incident was that it was the first of its kind and it breaks all diplomatic and security norms of the state of Egypt," said the group, which called on the authorities to quickly apprehend the kidnappers.

A bus with about fifty Palestinians on it was travelling from Rafah on the Egypt-Gaza border to Cairo airport when it was ambushed, the security sources said. Hamas' interior ministry confirmed that four Palestinians were kidnapped on their way to Cairo. "We urge the Egyptian interior ministry to secure the lives of the kidnapped passengers and free them," Gaza interior ministry spokesman Eyad al-Bazom said, adding that the bus was being escorted by Egyptian soldiers.

Spokesmen for Egypt's military and interior ministry could not be reached for comment. No group has claimed responsibility for the incident. Hamas has long had ties to the Egyptian Muslim Brotherhood that was ousted from power when former president Mohamed Mursi was overthrown by the army in 2013 after mass protests against his rule. The Egyptian government has accused Hamas of helping Islamist militants in Egypt's Sinai desert, which borders on Gaza, to attack its security forces. Hamas denies this.

A decision by an Egyptian court in June to cancel a previous ruling labelling Hamas a terrorist group raised speculation that relations between Egypt and Hamas may improve. Sinai is the focal point of an Islamist insurgency that aims to overthrow the government, and the most active militant group in the area is the Egyptian affiliate of Islamic State, Sinai Province.