Protests have escalated in major cities across Tanzania as opposition supporters denounce Wednesday's presidential and parliamentary elections as a sham.

Hundreds of demonstrators also crossed into Kenyan territory, barricading roads, lighting bonfires and tearing down posters of President Samia Suluhu Hassan along the way.

Kenyan police said two people died after fleeing running battles with Tanzanian police.

Protesters accuse the government of undermining democracy, as the main opposition leader is in jail and another opposition figure was disqualified from the election, bolstering Samia's chances of winning.

Anger grew on Thursday after the electoral commission started announcing results, with Samia getting nearly 95% of the vote in south-western Mbea province.

She has also taken the lead in many other constituencies on the mainland and in Zanzibar.

European Union (EU) lawmakers called the election a "fraud" that had been "unfolding for months".

Polling day itself was marred by clashes between opposition supporters and the police.

A day later, Tanzanian military chief Gen Jacob Mkunda blamed "bad characters who wish ill for this country" for the "damage to property and people" during the vote.

Gunfire was heard in the northern city of Mwanza, while clashes broke out in the capital, Dodoma, and the main city Dar es Salaam, which is under heavy security with major roads blocked.

Kenya has warned its citizens not to join protests at the border town of Namanga, where businesses were paralysed.

Tanzanian police fired tear gas to disperse the protesters who engaged them in running battles for most of the day.

The US Embassy in Tanzania reported that the road to Dar es Salaam's international airport was among several major routes that remained closed on Thursday.

An eyewitness told the BBC that he saw hundreds of protesters pouring into Mwanza city, which lies on the shores of Lake Victoria and has the biggest population after Dar es Salaam.

"After barely 10 minutes, we started hearing gunfire and tear gas explosions," he said.

"We see some injured people are being evacuated towards our way."

The government has ordered civil servants to work from home until Friday as tensions escalate.

Rights group Amnesty International said reports that a civilian and a police officer had been killed in clashes on Wednesday were "deeply disturbing".

A night-time curfew was imposed in Dar es Salaam, with sources telling the BBC that the city's Muhimbili Hospital had seen an influx of wounded patients.

Internet connectivity remains severely disrupted across the country - a situation Amnesty warns could further inflame the situation. It called on the authorities to allow unrestricted access to information.

In the meantime protesters are said to be using a walkie-talkie app, called Zello, to plan their next moves.

President Samia is widely expected to secure a second term after opposition candidates were barred from running.

The poll is also anticipated to be a shoo-in for her party, which has never lost an election since independence.

Tundu Lissu, the main opposition leader, is in jail on treason charges, which he denies, and his party boycotted the vote.

The only other serious contender, Luhaga Mpina of the ACT-Wazalendo party, was disqualified on legal technicalities.

Sixteen fringe parties, none of whom have historically had significant public support, were cleared to contest the elections.

Samia took office in 2021 as Tanzania's first female president following the death of President John Magufuli.

She was initially praised for easing political repression, but the political space has since narrowed, with her government accused of targeting critics through arrests and a wave of abductions.