(Updates casualty toll, Israel denies detaining Gaza fishermen, says own boat caught fire)
GAZA, Jan 24 (Reuters) - Israeli troops killed a Palestinian man on Friday and wounded another in a cross-border confrontation with protesters in the Gaza Strip, the Israeli army and Palestinian hospital officials said.
The shooting occurred as tensions ran high after Israeli forces killed two Palestinian militants in a Gaza air strike on Wednesday, blaming one of them for a rocket attack during the funeral of late prime minister Ariel Sharon earlier this month.
Palestinian hospital officials said Israeli troops had fired across the border into Gaza on Friday, killing a civilian aged 20 and wounding three other men, while three other Palestinians were injured by rubber bullets or tear gas inhalation.
An Israeli military official said the troops had fired at protest ringleaders after demonstrators hurled rocks and rolled burning tyres toward them.
In a separate incident, the Islamist Hamas-run Interior Ministry of Gaza said Israeli naval forces detained two Palestinian fishermen after setting their vessel on fire.
An Israeli military spokeswoman denied detaining any fishermen or setting fire to any Palestinian boats, adding that it was an Israeli naval vessel that caught fire due to a water tank malfunction, injuring 16 soldiers on board.
Israel often takes measures to enforce a six-mile (10-km) limit on how far Palestinian fishermen may venture out to sea.
After a period of unusual quiet around Gaza, Israel said on Tuesday there had been some 20 Palestinian rocket or mortar launches over the last month, and Prime Minister Benjamin Netanyahu vowed preemptive action against such threats.
On Sunday, an air strike wounded a Gaza man linked by Israel to other rocket launches last week. Israel said those attacks, which hurt no one but caused alarm in Israeli towns near Gaza, were the work of Iranian-backed Islamic Jihad. (Reporting by Nidal al-Mughrabi; Writing by Allyn Fisher-Ilan; Editing by Andrew Roche)