The Tunisian who knifed three people to death in a church in Nice, southern France, last week has tested positive for Covid-19, which could further delay him being questioned, according to judicial sources. Ibrahim Issaoui, 21, remains in hospital after being shot 14 times by police following the knife rampage at Nice's Notre-Dame basilica on Thursday. He is reportedly no longer in a critical condition but police have not been able to question him to date. Shouting "Allahu Akbar”, he beheaded a woman and killed two other people in Nice’s Notre-Dame Basilica last Thursday, in France's second deadly knife attack in two weeks with a suspected Islamist motive. Known to Tunisian police for violence and drug offences, he arrived in France only last month, having first crossed the Mediterranean to the Italian island of Lampedusa. Four more people were detained for questioning on Tuesday morning, including a 29-year-old man suspected of being in contact with Issaoui, say judicial sources. They were taken into custody in the Val-d'Oise department just north of Paris.