( CNN ) - The house of Palestinian Prime Minister Ismail Haniya came under rocket-propelled grenade fire Tuesday morning, the Hamas media office reported. There were no injuries.
Haniya lives in the Shati refugee camp on the outskirts of Gaza City.
At least 15 people have died in the fighting since Monday morning, according Fatah's secretary in Gaza. The deadly 24-hour period brought the death toll since factional fighting flared in May to more than 80.
Before the attack on Haniya's home, Hamas gunmen killed Jamal al-Jediyan, the top Fatah official in northern Gaza, Fatah sources said. His brother and cousin also died in the attack.
Later in the morning, Hamas gunmen surrounded the home of Fatah spokesman Maher Mekdad. His fate was not immediately known.
And on Tuesday, continued violence made it impossible for students to attend final exams, keeping 77,000 out of class.
Hamas fighters also destroyed the equipment at a Fatah-controlled TV station, according to a CNN journalist who witnessed the incident.
The internal violence between Fatah and Hamas has highlighted the weaknesses of the Palestinian unity government formed earlier this year.
Fatah forces are loyal to Palestinian Authority President Mahmoud Abbas. Hamas, an Islamic fundamentalist group, came to power in parliamentary elections in January 2006 after more than a decade of Fatah rule over the Palestinian Authority.
The leaders of both groups have called for calm, but security forces for each side have continued to battle each other in an attempt to control Gaza, despite numerous attempts to broker a cease-fire.
Palestinian medical sources said earlier Monday that seven people had been killed in Beit Hanoun, two died in Gaza City and one was killed in Jeblaya.
The fighting came after Egyptian negotiators thought they had secured another cease-fire between the two groups.
Monday's violence occurred after shots were fired near Haniya's residence and near a building where the Palestinian Cabinet was meeting. There were no casualties in either of those incidents.
On Sunday, members of Hamas kidnapped a member of a Fatah security team and threw him off the top floor of a 15-story building in Gaza City and killing him, officials with the Fatah-affiliated National Guard said.
The 20-year-old officer was with the Fatah-affiliated presidential guard, Palestinian sources said.
Early Sunday, Israeli aircraft launched strikes in Gaza City, the Israel Defense Forces said.
The airstrikes were "against the Islamic Jihad terrorist organization and violent offshoots of Fatah," the IDF said.
Tensions between Israel and the Palestinian territory have been rising in recent months. Israel claims militants in Gaza have fired hundreds of rockets into Israel, prompting the IDF to launch retaliatory strikes.