Thousands of people have turned out to pay their respects to a French priest murdered by Islamic State.

Around 2,000 people attended a funeral service for Father Jacques Hamel at a packed Rouen cathedral.

The 85-year-old was killed on the alter of his church in Normandy last week. 

The attackers took hostages during morning mass before being shot dead by French police outside the church.

Hundreds more gathered outside to watch on a giant screen as speakers including Fr Hamel's sister and Interior Minister Bernard Cazeneuve paid tribute to the late priest.

Speaking with a relative supporting her, the priest's sister Roselyne Hamel described him as "everyone's brother" and issued an appeal for people of different faiths to "learn to live together".

She said Fr Hamel had refused to become an officer in the French army because "he would have had to give orders to his men to kill other men, so he categorically refused".

In an emotional address, Fr Hamel's niece Jessica Deleporte said: "Like you, I choose respect, like you, I choose love, like you, I choose to fight."

Representatives of the local Muslim community are also expected to take part - delivering a clear message of condemnation and rejection of the attack.

France's main religious leaders called for unity and solidarity in the wake of the attack.

The Archbishop of Paris, Cardinal Andre Vingt-Trois, called on Catholics to "overcome hatred that comes in their heart" and not to "enter the game" of the Islamic State group that "wants to set children of the same family in opposition to each other".

Paris Imam Dalil Boubakeur said France's Muslims must push for a better training of Muslim clerics, and also called for a reform of French Muslim institutions to be on the agenda.

As a mark of solidarity, Muslims attended Catholic mass over the weekend in churches around France.

Over 100 Muslims were among those who gathered in Rouen to remember Father Jacques Hamel.

Rouen Archbishop Dominique Lebrun told the group: "I thank you in the name of all Christians. In this way you are affirming that you reject death and violence in the name of God."

The attendees were responding to a call by the French Muslim council CFCM to show their "solidarity and compassion" over the priest's murder on Tuesday.

A woman at a church in central Paris told Aljazeera: "I'm a practising Muslim and I came to share my sorrow and tell you that we are brothers and sisters."

She added: "What happened is beyond comprehension."