Israeli troops have killed two Palestinians in separate incidents when they opened fire near the border in the Gaza Strip, medical officials have said.

Ashraf al-Qudra, a spokesman for Gaza's emergency services, confirmed a man in his early 20s was shot dead by troops near the northern border, but said they had not yet been able to retrieve his body.

A spokeswoman for the Israeli military said troops had opened fire on an ‘armed Palestinian’, saying he had ‘fired at them first’.

In an unconnected incident earlier on Friday, Israeli border police killed a man and wounded another who had tried to cross the Egyptian border into Israel.

An Israeli security source said they were both unarmed Gazans.

The second was taken to hospital.

He said the incident took place in the middle of Israel's 240-kilometre border with the Egyptian Sinai.

On Thursday, Israeli armed forces killed a Palestinian fighter and wounded another two in a drone airstrike.

In the earlier incident, three men who were travelling in a car in Shejaiya, a neighborhood in the east of Gaza City, were injured when a tank shell struck their vehicle and another landed nearby, medics said.

One of them was critically wounded, while the other two were moderately hurt.

PHOTO CAPTION

Palestinian boys gather around the body of Hamas gunman Mahmoud al-Hegi during his funeral at a mosque in Gaza City July 12, 2012.

Al-Jazeera