70 dead as fighting intensifies in Yemen's Marib
The Houthis have been trying to seize oil-rich Marib, the government's last significant pocket of territory in the north, since February.
Two officials from pro-government forces told AFP that battles are raging on three fronts outside Marib city as the Houthis mount a concerted push.
The new toll comes after officials on Saturday announced 53 killed on both sides.
The 70 dead included 26 members of the pro-government forces and 44 from Houthi ranks, they said. The rebels rarely disclose their losses.
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One of the officials said that the rebels "are launching simultaneous attacks" in the areas of Kassara and Al-Mashjah, northwest of the city, and Jabal Murad in the south.
"They have made progress on the Kassara and Al-Mashjah fronts, but they have been thwarted on the Jabal Murad front," he told AFP.
The other official said that warplanes from the Saudi-led military coalition, which entered the Yemen conflict to support the government in 2015, launched airstrikes that "destroyed 12 Houthi military vehicles, including four tanks and a cannon".
The Iran-backed rebels in late 2014 overran the capital Sanaa, 120 kilometres to the west of Marib, along with much of northern Yemen.
The loss of Marib would be a heavy blow for the Yemeni government, currently based in the southern city of Aden, and for its Saudi backers.